Children were the latest victims as the crisis deepened in Sri Lanka.
The United Nations children's organisation, Unicef, said a number of children were killed in a government air strike on territory held by the Tamil Tiger rebels.
The Tigers claimed that the air strike hit an orphanage in the north-eastern Mullaitivu district and that 61 schoolgirls were killed, and 155 injured.
Unicef could not confirm the Tigers' figures, but had been able to establish that "children were injured and killed", said Junko Mitani, a spokeswoman for Unicef's Sri Lanka office.
The area hit by the air strike is cut off from the rest of Sri Lanka by the fighting.
European ceasefire monitors who were able to reach the site said they saw the bodies of 19 people aged between 17 and 20. The monitors said the orphanage building was still standing, and they believed the orphans had been evacuated before the air strike hit.
The Sri Lankan military insisted it had targeted a Tiger training camp and killed between 50 and 60 guerrillas.
It posted a photograph on its website which it claimed showed girls receiving military training at Tiger camps.
Within hours, a group regarded as a Tiger front threatened to target civilians in retaliatory attacks.
And just hours later, a suicide bomber struck in Colombo, killing seven people, three of them civilians.
The bomber appears to have targeted the Pakistani high commissioner's motorcade.
The suicide bomber was in an auto-rickshaw armed with a military fragmentation mine. He detonated the mine near the Sri Lankan President's residence as the Pakistani high commissioner, Bashir Wali Mohammed, passed in a convoy of cars.
Mr Mohammed escaped uninjured as the bomber missed his car but killed commandos in the car behind as well as three civilian bystanders.
It seems likely that the bomber mistook Mr Mohammed for a senior Sri Lankan official: he was travelling in a heavily armed military convoy close to the President's house.
But the Pakistani high commission told reporters there had been a specific threat against Mr Mohammed.
Fighting continued in the north around the Jaffna peninsula.
At least 100,000 people have fled their homes to escape the fighting around Jaffna and Trincomalee in the east, according to aid agencies.
Jaffna, home to Sri Lanka's largest Tamil community, was under curfew for most of the day.
Artillery fire continued over the Elephant Pass, the causeway linking the peninsula to rest of Sri Lanka, and on Kayts, a small island off the Jaffna coast.
Since last December, the government has been facing regular attacks on its military, which diplomats agree were blatant Tiger attempts to drag it into a war.
But under international pressure, the government reacted with restraint.
But it was while the world's attention was on Lebanon that the government launched the first ground offensive since a 2002 ceasefire, citing the Tigers' closure of a water supply near Trincomalee.
That offensive now looks to have been a mistake, after it enabled the Tigers to expand the fighting to Jaffna.
Norwegian mediators are still trying to get both sides to respect the ceasefire, but, after the Tigers refused peace talks over the weekend, the ceasefire appears to be little more than paper.