A grenade attack on a police truck in Kenya's port city of Mombasa killed one person and wounded four others, officials said Wednesday, the latest violence since deadly riots broke out on Monday.

"Grenade... hurled at a vehicle -- one fatality, two critical evacuated to hospital," the Kenya Red Cross said.

Initial reports suggested the person had been killed by the blast, but others said the fatality may have been one of the attackers.

"One person has been killed at the scene where the grenade occurred," a senior police officer said. "We believe he was one the attackers."

Police earlier Wednesday said that they had restored calm to the town, after violent protests erupted on Monday following the assassination of Muslim preacher Aboud Rogo Mohammed.

Hundreds of angry youths fought running battles with police -- looting churches, and torching cars. Rioters also attacked a police truck with a grenade on Tuesday, killing three officers and wounding over a dozen.

The cleric -- popularly known as Rogo -- was on US and UN sanctions lists for allegedly supporting neighbouring Somalia's Al-Qaeda-linked Shebab militants.

One person was also hacked to death in the riots on Monday, while several civilians were wounded. The reported fatality on Wednesday takes the total killed in the protests to five.