WASHINGTON - The horrific condition facing civilians in northeastern Sri Lanka--described as a "bloodbath" by the United Nations--demands immediate action by the United Nations Security Council, Amnesty International said today.

In the last few days, more than 400 people--including more than 100 children--are reported to have been killed in a two-day bombardment of the two-square-kilometer area designated as a "Safe Zone" by the Sri Lankan army. This brings the total estimated casualties to more than 7,000 killed and 13,000 injured since January. There are an estimated 50,000 civilians still trapped in the area.

Medical personnel in the area have told Amnesty International that the artillery barrage continued throughout the weekend. The Sri Lankan government has denied using artillery, instead blaming the Liberation Tigers of Tamil Eelam.

Both the Tigers and Sri Lankan military have been violating the laws of war. Over the last several months, the Tamil Tigers have used civilians trapped in the conflict zone as a buffer against government forces. When civilians have tried to flee, they have been attacked by the Tigers. The Sri Lankan military has in the past used heavy artillery, which is indiscriminate under the circumstances, causing civilian deaths and injuries.

"The controversy over who is responsible for these devastating attacks underlines the need for the Security Council to demand immediate access to the area by humanitarian organizations as well as U.N. observers," said Sam Zarifi, Amnesty International's Asia-Pacific director. "The Security Council should emphasize that both the government and the LTTE will be held fully accountable for any breaches of their obligations under international humanitarian and human rights law."

There are grounds to fear that the Sri Lankan military will launch an even heavier military offensive after May 13, when general elections end in neighboring India. India's powerful regional Tamil political parties have made protection of civilians in Sri Lanka a key election issue.

"There are real fears that the ‘bloodbath' will turn into a flood of misery after May 13. The Security Council must act on its responsibility to protect the civilians in Sri Lanka before hundreds more are killed and wounded by the two sides or succumb to malnutrition and disease," Zarifi said.

Amnesty International called on all international donors to Sri Lanka to ensure that their money is not used to fuel human rights abuses. In a joint letter to the government of Japan, Amnesty International, Human Rights Watch, the International Crisis Group, and the Global Centre for the Responsibility to Protect called on Japan, one of Sri Lanka's largest international donor, to support formal action by the Security Council and implement aid policies that help protect the rights of Sri Lankan civilians.

The Sri Lankan government has repeatedly claimed that it will stop the use of heavy artillery in the "Safe Zone."

"The Sri Lankan's frequently broken promises of not using heavy artillery against civilians shows that it is not a credible source of information," Zarifi said.

Amnesty International has urged the Sri Lankan authorities to allow immediate and unhindered access to the troubled areas--including the "No Fire Zone"--to international monitors and agencies, who can assess the situation first hand and help ensure that the humanitarian and human rights crisis is addressed.

Hospitals in northern Sri Lanka have become overrun with dead and wounded people after a weekend of shelling caused heavy civilian casualties in the region.

"Due to the huge number of injured civilians, the hospital is unable to give services to all patients," a local Sri Lankan doctor told Amnesty International. "Many wounded civilians are being left without treatment for more than 24 hours and more than half of hospital staff are not reporting for duty because their homes are under attack."

"Many civilians' temporary tarpaulin houses were shelled," confirmed the doctor.

Amnesty International has called on the government of Sri Lanka and the opposition Tamil Tigers.to take immediate action to prevent further civilian casualties.

"Civilians are suffering injuries and dying because both the Tigers and the government troops are violating international humanitarian law," said Zarifi. "The civilians caught in the crossfire also face an alarming lack of humanitarian aid including medical supplies, food and water."

The government's restrictions on media have escalated sharply in recent months. At least 16 media workers have been unlawfully killed in Sri Lanka since the beginning of 2006. Others have been arbitrarily detained, tortured and allegedly disappeared while in the custody of security forces. Last week, the Sri Lankan government expelled three British television journalists who had managed to provide the first uncensored information about conditions inside the internment camps housing tens of thousands of people displaced from the conflict area.