Article published on the 2009-02-19 Latest update 2009-02-19 11:48 TU
Holmes met Foreign Minister Rohitha Bogollagama in Colombo at the start of a three-day visit, during which he is expected to travel to the north-east to inspect government-run relief centres for people who have fled the fighting.
The LTTE on Thursday broke weeks of silence to accuse the airforce of killing more than 100 civilians in an attack on the small area that it still controls.
The government claimed that the Tigers were inventing such incidents.
The UN has accused the rebels of shooting civilians trying to leave the combat zone and appealed to the military to avoid civilian casualties.
The International Committee of the Red Cross (ICRC) on Thursday reported an "unfolding catastrophe" in the war zone, with trapped civilians short of food, medicine and shelter.
Sri Lanka's ambassador to Paris, Lionel Fernando, says the government is doing what it can for civilians and now it is up to the LTTE to surrender.
"One safe passage had been given to the west of Mullaitivu," he told RFI. "Then a second passage had been opened towards the sea, where the navy and the ICRC is helping out the civilians to come."
Local officials have told Fernando that 40,000 of the 112,000 people in the area have been taken out of Mullitaivu.
Fernando pours scorn on an LTTE call for a truce, made on Wednesday.
"How can you have a truce within the matter of 100 square kilometres?" he asks, pointing out that the Tigers used to control 80,000 square kilometres and so are now only a position to surrender.
The Sri Lankan government, which has banned journalists from going to the affected area, today repeated its opposition to a visit by British envoy, Des Browne.
Browne's appointment last week caused Colombo to accuse British Prime Minister Gordon Brown of acting unilaterally.