Sri Lanka ? Artillery shells tore through a hospital packed with wounded civilians in Sri Lanka’s war zone for a second day Wednesday, killing at least 50 people, setting an ambulance ablaze and forcing the medical staff to huddle in bunkers for safety, doctors said.

Health workers at the makeshift medical facility said they were so overwhelmed by the crush of the wounded and the unrelenting shelling of the area they could do little but give gauze and bandages to the roughly 1,000 patients waiting for treatment.

The strike on the hospital came as the government marched on with its offensive to destroy the reeling Tamil Tiger rebels and end their quarter-century quest for a separate homeland.

There has been a wave of artillery bombardments across the war zone that began over the weekend and has barely let up in five days, health workers said. The weekend attacks alone may have killed as many as 1,000 people, doctors said.

The government says its troops are not responsible for the shelling and that the military has not fired heavy weapons in the area in weeks.