At least four people have been killed after a device exploded inside a passenger van in the Kenyan capital Nairobi in what appears to be the first attack there since the deadly terrorist assault on a mall in September.
The explosion happened as the minibus was travelling from Eastleigh district of Nairobi to the city centre, said Benson Kibue, chief of police in Nairobi. Investigators believe an improvised explosive device was used in the attack that injured at least 25 others.
Sometimes called Kenya's "Little Mogadishu," Eastleigh is known for its large population of ethnic Somalis. The area came under fresh scrutiny by investigators following the September 21 attack on Nairobi's Westgate Mall, a bloody four-day siege in which at least 67 people were killed.
A Western official familiar with the Westgate attack investigation said last month that all four attackers were ethnic Somalis who had spent time in Eastleigh. All four gunmen arrived in Kenya in June and attended a gym in the area.
Al-Shabab claimed responsibility for the Westgate attack, saying it was in retribution for Kenya's involvement in Somalia. The group, which is linked to al Qaida, had threatened large-scale attacks for years, and it has said more will be carried out unless Kenya withdraws.
Kenya has been grappling with its large population of Somali refugees since the Westgate attack, with government officials announcing plans to speed up their return home. Nearly 500,000 Somali refugees live in Kenya, most of them in the sprawling Dadaab refugee settlement near the Somali border
In the last few years Somali refugee camps, particularly Dadaab, have been hit by a spate of blasts by grenades and other improvised explosive devices.
Last month Kenya, Somalia and the United Nations refugee agency signed an agreement saying the 475,000 registered Somali refugees inside Kenya will get support when they return to their homeland - if they choose to return.