By Joseph Akwiri
MOMBASA, Kenya (Reuters) - An attacker threw a grenade at a police vehicle in Kenya's port city of Mombasa on Thursday, wounding an officer and a civilian, a senior official said.
The city, a major tourist centre and the biggest port in east Africa, has suffered a string of gun and grenade attacks in recent months, largely blamed on the Islamist group al Shabaab, based in neighboring Somalia.
Officers had just picked up two suspects after getting information they were planning an unspecified crime, Mombasa county commissioner Nelson Marwa told journalists at the scene.
As the car left "their accomplice threw a grenade which exploded behind the police vehicle," he added.
Earlier in the evening, the government's National Disaster Operations Centre had said the blast was caused by an improvised explosive device.
Al Shabaab, which has fought a bloody seven year campaign to impose its interpretation of Islamic law inside Somalia, has said it wants to take revenge for Kenya's deployment of troops in the Horn of Africa nation.
(Additional reporting by George Obulutsa in Nairobi)