At least 10 people have been killed in an explosion in southern Sri Lanka, according to police.
A cabinet minister is among more than 20 people injured in the blast near the town of Matara, 160km south of the capital, Colombo, on Tuesday.
The Ministry of Defence said the explosion was a suicide attack by Tamil Tiger rebels.
Local residents said several government ministers were attending a function at the mosque to celebrate birthday of the prophet Mohammed at the time of the blast.
The ministry said Mahinda Wijesekara, the minister for post and telecommunications, was injured in the attack.
The Tamil Tigers have been fighting for a separate homeland for the ethnic Tamil minority in the north and east of the country for the past quarter of a century.
In recent weeks, a major Sri Lankan army offensive has inflicted a series of defeats on the Tamil Tiger forces, pushing the rebels into a narrow area of jungle in the north of Sri Lanka.
About 70,000 people have died in the past 25 years.