The United Nations has strongly condemned the bombing of a bus carrying South Korean tourists which killed four and injured 15 others.
The terrorist attack, which took place on Sunday near the Egyptian resort town of Taba, adjoining Israel, killed three Korean tourists and the Egyptian driver.
It was the first attack targeting tourists since the overthrow of Islamist president Mohamed Morsi in July that sparked off an Islamic insurgency, mostly against the police and army.
Ban Ki-moon "conveys his condolences to the families of the victims and to the governments of Egypt and the Republic of Korea," a UN spokesperson said in a statement on Sunday.
"He calls for the perpetrators to be brought to justice,” the statement added.
Sunday's bombing is expected to further damage Egypt's tourist industry – a top foreign currency earner - that has been decimated by three years of turmoil since the 2011 uprising that toppled autocrat Hosni Mubarak.
Dozens of Egyptian policemen and soldiers have been killed in bombings and shootings in the Sinai Peninsula and more recently in the Nile Delta and Cairo.
Scores of Egyptians and foreign tourists were killed between 2004 and 2006 in a wave of terrorist bombings in resorts in south Sinai.
In 1997, Islamist militants murdered 58 tourists and four Egyptians in a pharaonic temple in the southern Nile town of Luxor in their campaign for an Islamic state.