Kenyan officials appealed for calm last night after 15 people were killed and scores injured in attacks on two churches near the border with Somalia.
Sunday worshippers came under fire from guns and grenades in the north-eastern city of Garissa in attacks that resembled those used by the Nigerian Islamic militant group Boko Haram.
There were no immediate claims of responsibility for the killings, but Somali fighters from the al-Shabaab group have been blamed for a series of grenade attacks since Kenya sent troops into Somalia last October. Garissa, in Kenya's remote Northeastern Province, has been used as a base for operations against Somali Islamists.
A provincial administrator, James Ole Sereni, said: "The people who did this want to start a war between Christians and Muslims. This is the work of terrorists who want to divide Kenya's Christians and Muslims."
Most of the deaths came at the African Inland Church, a small wooden building in the town about 140 miles from the border. The mid-morning service was under way when masked men shot dead the police guards outside. The attackers then took the officers' weapons, went inside and opened fire on the congregation while other militants waited outside to target people trying to escape, police said. At least one grenade was thrown.
David Mwange, a churchgoer, told the Associated Press news agency: "We were deep in prayers preparing to give our offerings.
"We first had a loud bang from outside which we mistook to be coming from the rooftops. We then heard gunshots which made us to lie down. Within no time we had gunshots all over. Everybody was shouting and wailing in pain."
When reporters reached the scene they found overturned wooden benches littering the church and the body of a girl in a blue dress lying outside. Fifteen people were killed and 40 more injured, according to initial police estimates. Witnesses reported seeing either three or four gunmen in dark blue outfits and masks who fled on foot after the attack. In a simultaneous assault, grenades were thrown into the congregation at Garissa's Catholic Church, injuring at least three people.
The killings came two days after four international aid workers were kidnapped by gunmen in the nearby refugee complex at Dadaab, home to half a million Somalis who have fled war and famine at home. It is believed the Norwegian Refugee Council staff are being held for ransom inside Somalia.
The vast majority of the community in Garissa is ethnic Somali and Muslim. Most of the churchgoers are likely to have been government workers and their families, or contractors attached to the army garrison in the town. Community leaders were braced for reprisals last night.
The Kenyan defence forces – ill-prepared to fight counter-insurgency – have in many cases turned on their own population. Human rights groups and an investigation by The Independent confirmed that Kenyan police and army have launched revenge assaults on ethnic Somalis in response to previous terror attacks.