In August 2011 the Egyptian army launched a military campaign against armed insurgents in Sinai after security in the peninsula broke down after the 25 January uprising earlier the same year.
Even though clashes between armed militants and the army and police occurred frequently in Sinai under the rule of the Supreme Council for Armed Forces which ruled the country in the transitional period following the 2011 revolution, it had not witnessed the large-scale bombings that occurrred during the era of ousted president Hosni Mubarak.
From 2004 to 2006, more than 140 civilians -- mostly tourists -- were killed in blasts in the towns of Taba, Dahab and Sharm El-Sheikh.
The first official engagement of the army in Sinai was in the summer of 2011, in what was titled Operation Eagle. A similar operation was launched under Islamist ex-president Mohamed Morsi - Operation Sinai - after 16 Egyptian soldiers were killed on 5 August 2012 near the Rafah border.
While the low level attacks continued in Sinai under Morsi, they spiked drastically after he was ousted from the presidency in July 2013, following mass protests demanding his resignation on the anniversary of his first year in power.
The gas pipeline from Egypt to Israel and Jordan, has been attacked often since 2011. There were more than 17 attacks on the pipeline between February 2011 and June 2012 and between July 2013 and February 2014. Morsi's time in office was the only period in which the gas pipe attacks halted.
Ansar Beit Al-Maqdis, a Sinai-based jihadist group, claimed responsibly for the major attacks both in Sinai and around Egypt since the Morsi's ouster. However, a number of other Islamist insurgent groups are also active in Egypt.
Below, Ahram Online provides a timeline of attacks in Egypt since late 2012:
August 5, 2012: Suspected Islamist militants shoot 16 Egyptian border guards dead near Sinai's Rafah city, close to the intersection of the Egyptian, Palestinian and Israeli borders. The assailants also hijack an Egyptian armed vehicle and attempt to cross into Israel but are shot down by an Israeli aircraft. Investigations into the accident are still ongoing.
May 16, 2013: Seven police and army personnel are kidnapped by unknown militants near north Sinai's Al-Arish city. The conscripts are released the following week, after which the army announced that the release was a result of negotiation with the kidnappers and efforts of military intelligence as well as mediation by tribal sheikhs and Sinai locals.
While news of arrests and a military campaign against militants was reported after Morsi called for their arrest, no trial was reported thereafter.
July 5: Two days after the ouster of Morsi, five army and police officers are gunned down by Islamists in Al-Arish, a city which had become a hotbed for militant activity since 2011, with weekly attacks on police and army facilities and government buildings that, mostly, failed to leave casualties.
July 24: In an incident representing a shift in the methods of attack as well as location, a bomb is detonated at the Daqahliya governorate's security directorate in the Delta city of Mansoura, killing a police conscript and injuring over 25 people. Previous attacks since February 2011 had mostly involved the use of firearms and to a lesser extent rocket-propelled grenades (RPGs) and grenades.
The interior ministry blamed Islamist extremists; the final results of police and prosecutor's investigations were not announced.
August 14: After police forces disperse the main pro-Morsi encampments in Cairo and leave hundreds of dead protesters in their wake, armed Islamists launch RPGs at the town of Kerdasa's police station in Giza, killing 11 officers and then reportedly securing control of the town.
Police returned to Kerdasa in September to arrest suspects involved in the attack and cleared it of armed militants.
August 19: The bloodiest militant attack so far happens when two vehicles transporting police conscripts near Sinai's Rafah – on their way home for a holiday, according to police statements – were attacked by militants using RPGs. Twenty-five of the conscripts are killed in the attack. The prime suspect, whom security sources said was a jihadist militant called Adel-Habbara, is arrested later in August and is now being tried in criminal court.
September 5: A failed assassination attempt on Egypt’s Interior Minister Mohamed Ibrahim takes place in Cairo. A suicide bomber detonates a car bomb close to Ibrahim’s security convoy, as seen in the video of the group claiming the attack, Sinai-based jihadists Ansar Beit Al-Maqdis.
September 11: A car bomb explodes at the military intelligence building in the Sinai city of Rafah near the Gaza border, killing six soldiers and injuring 17 soldiers and civilians. Ansar Beit Al-Maqdis claims the attack.
October 7: Nine police and army officers and conscripts are killed in two attacks: a drive-by shooting on a military patrol near Ismailia, where an army officer and six conscripts are killed, and a bombing at the security directorate in Sinai's Al-Tor city which leaves three police officers dead.
Later that evening, an RPG is fired at a satellite link in Cairo's upscale southern district of Maadi, causing little damage. The attack is claimed by another militant group active in Sinai called Kataeb Al-Forqan.
November 17: National security officer Mohamed Mabrouk – involved in investigations of the Muslim Brotherhood and jihadist groups – is assassinated by gunmen near his home in eastern Cairo. Ansar Beit Al-Maqdis claims the killing a few days later.
November 20: A car bomb is detonated on the Arish-Rafah highway in North Sinai, killing 11 army conscripts and injuring 17 others. The attack is claimed by Ansar Beit Al-Maqdis, who later release a video recording of it.
December 24: A large explosion, apparently a car bomb and possibly more than one, detonates at the Daqahliya governorate's security directorate in the Nile Delta city of Mansoura, killing 15 and injuring over 130 policemen and civilians. Ansar Beit Al-Maqdis claims the attack and several militant suspects are rounded up and questioned by police, who release videos of testimonies from primary suspects.
January 23, 2014: Five Egyptian policemen are killed and another two wounded in a drive-by shooting on a checkpoint in Beni Suef governorate, around 200 km south of Cairo. Later in February, the interior ministry directly accuses Muslim Brotherhood militants for the shooting, the first time it has levelled blame at the Islamic group for an attack since Morsi's ouster.
January 24: Four separate bomb attacks hit Greater Cairo on the eve of the 25 January 2011 revolution's third anniversary, killing six people and injuring dozens. The bombs target Cairo's central police headquarters, a police unit stationed near a metro station in Giza’s Dokki district, a police station in Giza's Al-Talbiya district and another near a government building in Giza's Haram district.
The Museum of Islamic Art, across the street from the central police headquarters, suffers extensive damage as a result of the explosion. The other two bombs were smaller in magnitude.
January 25: Five soldiers – the crew of a military helicopter – are killed after their craft is hit by a surface-to-air missile in Sinai. The attack was claimed by Ansar Beit Al-Maqdis.
January 28: General Mohamed Said, an aid to the interior minister, is shot dead near his home in Giza's Haram district by unknown assailants riding a motorcycle.
February 16: At least four are killed in an explosion on a tourist bus in the Red Sea resort town of Taba in South Sinai. The dead include the bus driver and three South Korean tourists. Fourteen others are injured. The choice by militants of a tourist bus containing civilians marks the first assault on a non-state target in the months-long string of bombings since Morsi's ouster. The last major attack on tourists was in April 2006, when a series of bombs rocked the Red Sea resort town of Dahab in South Sinai, killing 23 and wounding at least 80.
While the above timeline encompasses the deadliest attacks to have occurred during the past two years, dozens more of attempted attacks have taken place, mainly in the Sinai Peninsula, the majority of which have led to limited injuries.
Attacks against security personnel are frequent and so not all deaths have been included in the timeline. Only major attacks have been noted.
The military has also announced the killing of dozens of suspected militants and the razing of dozens of buildings that were being used for militant activity since its offensive campaigns in Sinai began in summer 2013.