Sri Lankan Tamil Tiger rebel planes bombed two oil facilities near the capital on Sunday, causing minor damage and tripping air defences that plunged the city into darkness, the air force said.
Colombo residents said they heard explosions and gunfire as the military responded to the air raid around 1:50 am (2020 GMT). Hospital officials said six people were admitted for injuries after the attacks, and two were in intensive care.
The early morning attack was only the third air strike ever by the Liberation Tigers of Tamil Eelam, or LTTE, who are fighting for an independent homeland for ethnic minority Tamils in the north and east of the Indian Ocean island.
"They dropped four bombs ... there was no human damage," a defence ministry spokesman said.
Two bombs landed in an area called Muthurajawela, north of the city, one damaging a water pipeline at a crude oil pumping station and the other striking a fire hut at a Shell gas facility, he said.
"There was an explosion and a fire. There has been some damage, power failure ... (But) there has been no damage to our storage tanks or pipeline," said Rimoe Saldin, finance director at Shell Gas.