Sri Lanka's Tamil Tiger rebels have accused the government of carrying out "genocidal" attacks on people in areas in the north-east under their control.
The attacks have killed and wounded civilians, rebel leaders say
And they criticised the international community for failing to condemn the two days of airstrikes by the military, in a statement on a pro-rebel website.
Thousands of people fled their homes on Wednesday to escape the strikes.
The attacks were in response to a suicide attack on army headquarters, which killed at least eight people.
The heavy firing has now eased, but both sides have vowed to retaliate if they are attacked again.
Many fear further violence could shatter the fragile four-year-old ceasefire.
In its statement, the Liberation Tigers of Tamil Eelam (LTTE) said the Sri Lankan government, "has violated gravely and totally the ceasefire agreement".
It called on the international community to "strongly condemn the genocidal attempt on the Tamil speaking people, the brutal attacks of state terrorism".
And the group expressed its "distress and dissatisfaction" at the international community's "absence of concern" over the attacks, the statement carried by the Tamilnet website said.
Glimmer of hope
Army spokesman Brigadier Prasad Samarasinghe said there had been no further strikes overnight, and a highway connecting the south to the north have now been reopened.
The road was closed after Tuesday's suicide bombing on the army headquarters in the capital Colombo.
A woman who made herself appear heavily pregnant to conceal the explosives is believed to have carried out the attack, which seriously wounded army chief Lt Gen Sarath Fonseka.
The rebels have denied being behind recent bomb attacks, although experts believe Tuesday's attack bears all the hallmarks of the Tigers.
The government's responding airstrikes on the rebel stronghold of Trincomalee in the north-east had killed at least 15 people, one Tamil leader said.
Up to 40,000 people have moved north to the safety of the jungle, local officials told the BBC.
International truce monitors are now in Trincomalee to assess the situation, and say the hiatus offers a glimmer of hope, the BBC's Dumeetha Luthra in Colombo reports.