Attackers hurled a grenade Thursday at British tourists in Kenya but it failed to explode, police said, in a rare attack specifically targeting foreign visitors who are key to the economy.
The tourists came under attack while travelling by road from the Indian Ocean coastal resort of Diani to Kenya's main port of Mombasa, a mainly Muslim region whose white-sand beaches are popular with tourist but which is also troubled by extremist groups and religious tensions.
"The grenade has been detonated safely by experts," said Robert Kitur, police chief for the Mombasa, where the attack took place.
"We are investigating the incident and looking for the man who threw the grenade at the tourists and fled."
The tourists continued on their way to a wildlife safari at one of Kenya's world famous national parks.
Tourism is a key multi-million earner of foreign currency for Kenya.
The British High Commission in Kenya said it was "aware of a failed grenade attack on a vehicle near Mombasa", adding they were "looking into whether any British nationals were involved and stand ready to provide consular assistance if needed".
The attack comes as Kenya celebrates its 50 years of independence from former colonial rulers Britain.
Since Kenya invaded southern Somalia in October 2011 to help oust Al-Qaeda-linked Shebab insurgents, it has seen a wave of grenade attacks.
Home grown groups including the Islamist Al-Hijra group, a radical organisation formerly known as the Muslim Youth Center, operate on Kenya's coast and have been linked to the Shebab.
Several radical Muslim preachers have been assassinated in Mombasa sparking riots by their supporters, who have accused the police of carrying out the killings, claims they strongly deny.
Grenades have been hurled into restaurants in Mombasa and crowded areas in the capital Nairobi, as well as a string of attacks in the remote northeast region bordering Somalia.
The Shebab also claimed the brutal September assault on Nairobi's upmarket Westgate mall in which at least 67 people died in a four-day seige, a centre popular with foreigners.
However, such grenades attacks have in the past rarely targeted tourists.
In September 2011 gunmen killed a British man David Tebbutt and kidnapped his wife Judith -- who was held for six months before being released -- who were on holiday at a Kenyan coastal resort close to the Somali border.
Three weeks later, disabled Frenchwoman Marie Dedieu was kidnapped from her home on Kenya's Manda island and later died in captivity in Somalia.
Police said they had beefed up security.
"We are appealing to everybody to exercise caution, especially over this festive season, and to share information with security agencies to win the war on terror," said Kitur.
"We have intensified security at tourist hotels and other vital installations to avert terrorism attacks."