COLOMBO, Sri Lanka - A top Sri Lankan government health official says witnesses are reporting heavy civilian casualties in fighting over the past week in northern Sri Lanka.
Dr. Thurairajah Varatharajah, the top government health official in the Mullaittivu district, says witnesses claim 250 to 300 civilians were killed.
He adds that hospital records show more than 1,100 were wounded.
The report came as the government pledged to refrain from launching attacks inside a civilian refuge area set up in the war zone.
Concerns have grown over the safety of civilians trapped inside rebel-held territory amid a government offensive aimed at crushing the separatist Tamil Tigers rebels.
The Red Cross estimates 250,000 civilians have fled to the jungle where fighting is taking place.
In Ottawa, meanwhile, Foreign Affairs Minister Lawrence Cannon expressed Canada's concern over civilian casualties in Sri Lanka.
"Canada is deeply concerned by the ongoing conflict in Sri Lanka," said Cannon. "Recent developments underline the urgent need for progress toward a meaningful and durable political solution."
He says Canada will continue to deliver strong messages to all parties to the conflict about the importance of a return to the peace process and the need to promote and protect the values of freedom, human rights and the rule of law.
Canada wants all parties to allow full, safe and unhindered access for humanitarian workers, and ensure the safe and voluntary movement of civilians from combat zones.
Varatharajah, the Sri Lankan health officials, said by telephone that at least 1,140 civilians -- 248 of them younger than 15 -- were wounded in the fighting and brought to three hospitals in the district.
The number killed was difficult to count because many civilians had stopped bringing dead relatives to the hospital amid the heavy fighting, he said.
"In my opinion, there are a lot of deaths. More than 250 to 300," he said, adding his estimate was based on reports from residents who came to the hospitals from the war zone.
Earlier, a letter in Varatharajah's name with similar estimates had been sent to The Associated Press by another government health official, who had provided accurate information in the past.
Varatharajah said he had not written the earlier letter.
The United Nations said dozens of its workers and their relatives came under artillery fire they believed was from government troops as they sought refuge inside the government declared "safe zone" for ethnic Tamil civilians on the weekend.
The military denied firing into the area during its offensive to root the Tamil Tiger rebels from the northeast.
"If they came under fire, then definitely it has been done by the LTTE," military spokesman Brig. Udaya Nanayakkara said, referring to the rebels by their formal name, the Liberation Tigers of Tamil Eelam.
Amid the reports of rising casualties, Indian External Affairs Minister Pranab Mukherjee rushed to Sri Lanka on Tuesday night to meet with top officials, including President Mahinda Rajapaksa.
The conflict is of special concern to India, home to some 56 million Tamils.
During the late-night meeting, Rajapaksa gave assurances Sri Lankan forces would respect the safe zone to "minimize the effects of conflict on Tamil civilians," according to nearly identical statements released by India and Sri Lanka on Wednesday.
"We are concerned with the civilians. I requested to the president to take care of these civilians," Mukherjee told reporters Wednesday.
The United Nations' local office sent a private email to its New York headquarters, describing how its staff in the "safe zone" came under fire several times on the weekend. The memo, which was obtained by The Associated Press on Wednesday, said the staff believed the fire was from Sri Lankan troops.
"Fortunately, because of good preparation, all staff and dependents were in hastily built bunkers and only one staff member was injured in the leg," the memo said.
"But all around them was the carnage from casualties from people who may have thought they would be safer being near the UN. Sadly, they were wrong that night."
Human rights groups and diplomats have expressed concerns for the civilians trapped in the shrinking territory still under rebel control -- an area of about 300 square kilometres.
UN spokesman Gordon Weiss said his staff has seen "dozens of people killed and wounded" in the refuge over the past few days, including 10 civilians killed Monday. He said he did not know who was responsible for firing in the area.
But a local health official, speaking on condition of anonymity for fear of reprisals from the government, said he believed the government was responsible for the casualties because of the direction from which the fire came.
The Red Cross appealed to both sides Tuesday to allow the civilians to flee to safety.
"People are being caught in the crossfire, hospitals and ambulances have been hit by shelling and several aid workers have been injured while evacuating the wounded," said Jacques de Maio, the International Committee of the Red Cross head of operations for South Asia.
Nanayakkara, the military spokesman, said 3,141 civilians have fled to the government-controlled territory this month.
Rebels continue to pull their forces and civilians into the last remaining areas of dense jungle still under their control. Government forces captured Mullaittivu, the last town held by the rebels, on Sunday.
The Tamil Tigers have fought since 1983 to create a separate state for minority Tamils, who have suffered decades of marginalization at the hands of governments controlled by the Sinhalese majority. More than 70,000 people have been killed in the civil war.
