The Sri Lankan military says a female suicide bomber blew herself up in the main railway station in the capital Sunday, killing at least 11 people and wounding about 100 others.
Witnesses said the woman detonated the bomb on a platform crowded with commuters. Hospital workers said some children were among the victims.
No group has claimed responsibility for the attack in Colombo, but the military is blaming Tamil Tiger rebels.
Earlier Sunday a hand grenade exploded at the Colombo Zoo, wounding several people.
Security throughout the capital is tight for Sri Lanka's 60th independence day celebrations Monday.
Some information for this report was provided by AFP, AP and Reuters.