A group of attackers threw a grenade at a bus in the Kenyan capital of Nairobi, killing at least four people, according to the country’s Interior Ministry.
The Kenya Red Cross said on its Twitter account that 15 injured people were taken to a hospital. The incident happened in Pangani, northeast of the city center and near the suburb of Eastleigh.
“The attack is an unfortunate and cowardice incident which will not be tolerated,” the Interior Ministry said on Twitter.
The blast comes as Kenya marked the 50th anniversary of independence from the U.K. this week and almost three months after an attack on the Westgate Mall left 67 people dead, which was claimed by al-Shabaab, an al-Qaeda-linked militant group based in neighboring Somalia.
Clashes have taken place before in Eastleigh, an enclave dominated by ethnic Somalis. At least five attacks took place between September and December last year and another blast was reported in March.
“We are still at the scene of crime, verifying facts,” Police Inspector General David Kimaiyo said by phone.
Kenya deployed troops to Somalia two years ago, blaming the Islamists for a series of kidnappings and the murder of a British tourist. That prompted a threat of retaliation from al-Shabaab. The Kenyan forces have since joined an African Union mission in the Horn of Africa country.