KABUL: Afghan insurgents captured two US soldiers and are holding them in southern Logar province, a Taleban fighter said Saturday.

NATO confirmed two American soldiers were missing in eastern Afghanistan, hours after reporting that five other US soldiers had been killed in bomb attacks.

The missing soldiers left their compound late Friday "and did not return", a statement from NATO's International Security Assistance Force (ISAF) said.

Their vehicle had been recovered in Logar province, an official said. "Nobody has been found but there are reports that there may be a casualty and that the body has been removed from the scene," a military official said, speaking on condition of anonymity.

ISAF said a road and air search had been launched.

A Reuters correspondent in Logar heard local radio broadcast appeals offering a $20,000 reward for information leading to the safe release of the two.

"Early this morning two coalition personnel went missing. They are believed to have been captured by insurgents somewhere in Logar province," the broadcast said. "They may have been separated from one another or maybe in the process of being moved to another location."

A Taleban spokesman told Reuters three ISAF servicemen had been captured but one had died. He did not elaborate.

The two US personnel were last seen wearing standard US military camouflage, the radio broadcast said.

One was described as about six feet tall weighing 100 kg with blond hair and brown eyes. The other was described as 86 kg, bald with a thin moustache. Both men have tattoos, the broadcast said.

There is believed to be only one other ISAF soldier being held by the Taleban, who released a video of him last Christmas.

Officials said earlier that five American soldiers died Saturday in bombings in southern Afghanistan where international forces are stepping up the fight against the Taleban.

Four of the victims died in a single blast, NATO said in a statement without specifying nationalities nor providing further details. A fifth service member was killed in a separate attack in the south, NATO said.

US officials confirmed all five were Americans.

The latest deaths bring to 75 the number of international troops killed in Afghanistan this month, including 56 Americans.

The US-led force is ramping up operations against the Taleban in their southern strongholds, hoping to enable the Afghan government to expand its control in the volatile region.

Rising casualty tolls, however, are eroding support for the war in Afghanistan even as US President Barack Obama has sent thousands of reinforcements to try to turn back the tide against the coalition forces.

On Tuesday, an international conference in Kabul endorsed President Hamid Karzai's plan for Afghan security forces to assume responsibility for protecting the country by the end of 2014. Obama has pledged to begin removing US troops starting in July 2011, although he has linked the drawdown to security conditions on the ground.

In the eastern province of Khost, a candidate in upcoming parliamentary elections died late Friday of wounds suffered when a bomb exploded earlier in the day in a mosque in the Mando Zayi district, according to local health director Amir Pacha.

The candidate, Maulvi Saydullah, was making a speech inside the mosque when the blast went off. His bodyguards and at least 15 other civilians were also hurt, officials said.

Afghanistan is due to hold national parliamentary elections Sept. 18 despite fears that they could provoke a surge in Taleban attacks.