The bombing comes as the country prepares to celebrate 60 years of independence from British colonial rule on February 04 and the capital is under a tight security blanket.
Police have blamed the Tamil Tigers for earlier bombings which have targeted civilians.
Sri Lanka pulled out of a ceasefire with the Tamil Tigers, who have been fighting for a separate state in the island for nearly three decades in January.
Go to front page at www.lbo.lk or click here for updates.