Rebels say they plan to intensify attacks against the government
The military in the Philippines says communist rebels have ambushed an army vehicle, killing five soldiers and wounding two others.
The landmine and gunfire attack happened in Surigao del Norte province, in the south of the country.
Rebels seized assault rifles, a laptop computer and the soldiers' personal belongings, an army spokesman said.
The latest ambush came after talks held in Norway between rebel and government representatives broke down.
A rebel spokesman, Fidel Agcaoili, said before the latest attack that New People's Army guerrillas would take advantage of "crisis conditions" faced by President Gloria Arroyo and step up its long campaign.
Peace talks held sporadically since 2004 are unlikely to resume, he said, until Mrs Arroyo's term ends in 2010.
The peace talks held in Oslo ended on Sunday with no agreement over what kind of ceasefire should be agreed, officials have revealed.
Government representatives reportedly wanted an indefinite ceasefire as a condition for resuming talks.
The rebels rejected that demand, Mr Agcaoili said, in favour of a truce that would take effect only during formal talks as a show of goodwill.
An annual tradition has evolved in which a truce is declared for two days over Christmas and two days over the New Year, but that appears uncertain now.
Mrs Arroyo has said in the past that she would wipe out the communists by 2010.
Meanwhile, her government withstood a fourth impeachment motion this week.
She has been accused of corruption and the condoning of massive human rights violations by the military, but denies any wrongdoing.
Her supporters have been trying to promote moves to amend the constitution to extend her time in office, something her respected predecessor Fidel Ramos warned against.
"It's too late now, at this time, to be talking about charter change," said Mr Ramos, a retired general who led the peaceful 1986 coup against the late dictator Ferdinand Marcos.
Opposition politicians and some Catholic bishops have called for demonstrations on 12 December in Manila's business district, to protest against any changes to the constitution.
Efforts to dislodge Mrs Arroyo have been blocked by her control of the House of Representatives and by her support within the army.