With the Philippine hostage crisis entering its third week, fresh attempts were made yesterday to break the deadlock.
President Joseph Estrada flew to the south of the country in the hope of reviving negotiations with Muslim rebels holding the 21 hostages, while the European Union resolved to send its most senior diplomat to the Philippines.
The EU's decision to dispatch Javier Solana, taken at a meeting of EU foreign ministers in Portugal, reflects Europe's concerns about the hostages' welfare.
The group being held by Abu Sayyaf guerrillas on the southern island of Jolo includes three Germans, two French nationals and two Finns, as well as 10 Malaysians, a Filipino, a Lebanese woman and a South African couple.
With pressure mounting on the Manila government to achieve a peaceful conclusion to the crisis, fears for the safety of the captives remain high. Abu Sayyaf rebels killed 13soldiers yesterday during a clash with troops trying torescue a separate group of Filipino hostages on the nearby island of Basilan. Three rebels died in the fighting, in the coastal town of Lantawan.
Meanwhile, troops surrounding the guerrilla hide-out on Jolo fired mortar shells at the rebels' defence lines, and a spokesman for Mr Estrada said a military operation to rescue the hostages might be launched if negotiations dragged on too long. The President, who had maintained a low profile since the hostages were kidnapped from the Malaysian resort island of Sipadan on Easter Day, flew to the city of Zamboanga, 500 miles south of Manila.
"We are determined to save the hostages and not put them in harm's way" he said in a speech to local officials and military personnel.
Mr Estrada visited wounded soldiers at a hospital at the military's southern command headquarters and briefly met the government's hostage negotiator, Nur Misuari.
Afterwards the President, who was wearing dark glasses and a military camouflage uniform, said: "I hope that the kidnappers will realise that keeping the hostages will serve no useful purpose whatsoever."
Warning the kidnappers that they faced armed retaliation, Mr Estrada said: 'This is a direct challenge to our government. If they persist in engaging in terrorist acts, we will give them the full might of our armed forces. Whatever happens, whatever we have to do, we will not allow our country to be dismembered."
Abu Sayyaf, the smaller of two guerrilla organisations seeking an independent Islamic state in parts of the southern Philippines, has demanded the release of three Muslim extremists in jail in the United States, including Ramzi Yousef, mastermind of the 1993 bombing of the World Trade Center in New York.
The EU's decision to send Mr Solana, the head of foreign and security policy, to the Philippines is a clear sign that European countries are losing patience with the Manila government. The EU rarely, ifever, sends envoys to intervene directly in hostage-taking episodes.
The foreign ministers issued a statement condemning the kidnapping of the 21 tourists and resort workers, and said they would "spare no effort to secure their safety and early release".
They said Mr Solana, who will leave for Manila today, would not be a mediator, but would "convey personally to the Philippine government the EU's message concerning the safety of the hostages".
Some 3,000 Muslim fighters from a regional militia began arriving yesterday to join a 2,000-strong military force surrounding the rebels' jungle camp at Talipao on Jolo. A cameraman and journalist who visited the camp at the weekend said the hostages were "haggard but scared". One of them, a German woman, was lying on a makeshift stretcher.
The woman is believed to be suffering from hypertension, and a Filipino doctor who visited the hostages last week warned that she might havea stroke if she remained in captivity.
Mr Estrada's spokesman, Ricardo Puno, said yesterday: "If it appears that the hostages are being treated well. If food and medicines are allowed into the location and there are no reports of abuse or torture, then we will give this every possible opportunity to be resolved in a peaceful manner."
But, he added: "If the situation has been extended too long and clearly a negotiated settlement would not result in anything positive or productive, then I am sure some thought would be given to [a military raid]."
On Basilan, Abu Sayyaf is believed to be still holding eight of 29 Filipinos taken hostage two months ago. At least six of them have been killed. On Saturday troops found the headless corpses of two teachers thought to have been killed just before soldiers attacked the base last week and rescued 15 of the captives.
Six people were killed in two bomb attacks on buses in the southern Philippines at the weekend. The blasts were blamed on the Moro Islamic Liberation Front, the larger separatist organisation.