At least one person has been killed and three people injured in an explosion in a suburb of Colombo, the Sri Lankan capital, a police spokesman has said.

The explosion occurred on Thursday near a Buddhist temple in Borelesgamuwa, Brigadier Udaya Nanayakkara said.

Police believe the blast was a suicide attack targeting a vehicle convoy carrying Maithripala Sirisena, the country's agriculture minister, he said.

Minelle Fernandez, Al Jazeera's correspondent in Colombo, said: "The government's media centre for national security has confirmed that the explosion took place a very short while ago."

Sri Lanka has blamed previous attacks across the island on fighters from the Liberation Tigers of Tamil Eelam (LTTE).

The LTTE, or Tamil Tigers, have been fighting for a separate homeland for Sri Lanka's ethic Tamils since 1972.