Update 18 May 09.00: There are reports that the LTTE leader has been killed. The cessation announced informally by the Tigers remains unconfirmed. There are conflicting reports of civilians trapped or released, with the UN still concerned. A spokesperson from the Chatham House think-tank in London has expressed worries that a bloodbath is still possible until the Sri Lankan government accepts that the LTTE have surrendered, that international law applies and until satellite images are examined openly and media access granted.
The Sri Lankan government and the Liberation Tigers of Tamil Eelam (LTTE) must immediately heed demands by the United Nations Security Council and similar calls made by US President Barack Obama and allow tens of thousands of civilians to leave the 'No Fire Zone', Amnesty International says.
The call came as fierce fighting was reported on Sunday 17 May in a tiny enclave of northern Sri Lanka - even as the country’s president declared victory in a 25-year civil war against Tamil separatist rebels.
The Sri Lankan military said it had for the first time secured the entire coastline, cutting off escape by sea, and had killed at least 70 rebel fighters as they tried to flee from their final refuge, a piece of sandy land no more than 1.2 square miles in size, reports the New York Times.
Horrific stories of atrocities and suicides are emerging from the war-torn country, although the government is preventing journalists from reporting from the war-zone. It also stands accused of blocking UN intervention.
Later in the day, Tamil rebels declared a ceasefire and "decided to silence our guns", said a pro-Tamil website.
"This battle has reached its bitter end," declared Selvarasa Pathmanathan, the Tigers' chief of international relations, in a statement on Tamilnet.
A later statement on the sitee appeared to modify the Tigers' position. Mr Pathmanathan said the LTTE was "prepared to silence its guns if that is what needed by the international community to save the life and dignity of the Tamil people".
The situation remains uncertain.
US President Barack Obama warned late last week that "without urgent action, this humanitarian crisis could turn into a catastrophe". He condemned the LTTE's use of civilians as 'human shields', urged the Sri Lankan government to stop the "indiscriminate shelling" in the area and asked that humanitarian agencies have access to the civilians who are trapped between the warring parties and those displaced people within Sri Lanka so they can receive the additional support needed
Amnesty International welcomed the Security Council's statement as a first step in addressing the humanitarian and human rights crisis in Sri Lanka but called for an end to the use of heavy calibre weapons. It also called for the UN, the Red Cross (ICRC) and other humanitarian organisations to be allowed immediate access to around 50,000 civilian trapped in the 'No Fire Zone' on the island's north east coast.
Sam Zarifi, Amnesty International's Asia-Pacific Director, said: "The Security Council must now ensure that its demands are promptly implemented, that the situation in Sri Lanka is formally put on the Council's agenda and kept under close review."
He went on: "'It also needs to address accountability for the grave violations of international humanitarian and human rights law by both parties in future."
Amnesty International welcomed separate statements from the Security Council and President Obama condemning the LTTE for its use of civilians as human shields and calling on the government to take urgent action to ensure the safety of civilians. The Security Council told the Sri Lankan government to fulfil its commitment not to use heavy calibre weapons in areas with high concentrations of civilians - a promise it has broken in recent weeks - which has caused the death of many civilians.
Amnesty International also urged the Security Council to emphasise individual responsibility for crimes under international law and to ensure the creation of a commission of inquiry as a first step towards establishing accountability for alleged breaches of international humanitarian and human rights law.
Amnesty has repeatedly condemned both the LTTE and the Sri Lankan military for serious violations of international humanitarian law, including war crimes. The LTTE have forcibly trapped civilians in the conflict zone for use as human shields against government forces. The Sri Lankan military has in the past used heavy artillery, which is indiscriminate under the circumstances, causing civilian deaths and injuries.