The Sri Lankan government launched air strikes on territory controlled by the Tamil Tiger guerillas, hours after a rebel attack on a bus left at least 64 people dead. The bus attack appears to be the deadliest incident since the government and rebels signed a 2002 ceasefire agreement, which many say is an agreement in name only.
Military sources say Sri Lankan fighter jets struck rebel targets near the town of Mullativu, in the east of the country.
There is no word yet on casualties or damage caused by the air strikes.
They come in retaliation for an incident earlier in which a landmine was detonated under a bus full of civilians on a remote road in Anuradhapura district, 200-ilometers northeast of the capital Colombo.
Witnesses say the bus was turned on its side by the force of the blast, and was left covered by broken glass and blood. Children were among the victims.
Officials immediately blamed the Tamil Tigers for the attack, in part because of the group's frequent use of landmines in attacks on military targets in the past. But they say retaliation for the attack would be limited.
Paikiasothy Saravanamuttu, with the Center for Policy Alternatives in Colombo, says the government remains committed to peace talks.
"As to whether this will constitute the first incident or catalyst for an outbreak of full blown hostilities remains to be seen," Saravanamuttu says. "I must emphasize that the government is on record as having said that they do not want to go to war and they want to pursue the negotiated option."
Hundreds of people have died in recent months in a series of retaliatory attacks between government forces and the rebels, which want greater rights for Sri Lanka's ethnic Tamil minority. The group began its campaign against the government in 1983, because of what they say is widespread repression of Tamils by Sri Lanka's Sinhalese majority.
The two sides signed a ceasefire in 2002, which was negotiated by Norwegian facilitators. Despite the wave of violence, both sides claim to uphold the truce.
Tamil Tigers leaders deny involvement in the bus attack. A statement on the rebel Web page says that paramilitary forces loyal to the government are behind the attack, which they say was an attempt to generate negative publicity about the rebels.
Last week, the Tamil Tiger leaders walked out of peace talks that were to be held in Norway. That prompted the Norwegian mediators to ask both the government and rebels for a formal recommitment to the peace process.
The government has said it wants the peace process to continue. The rebel leaders have yet to respond.