Taliban-style bomb attacks killed five US soldiers in Afghanistan yesterday, Nato said, as the death toll of foreign soldiers in the nine-year Afghan war climbed towards the 2,000 mark.
Nato's International Security Assistance Force (ISAF) said the five had died in two separate attacks involving improvised explosive devices (IEDs), the main weapon deployed by the Taliban in their insurgency.
An ISAF spokesman confirmed all five were Americans.
An incident early in the day claimed the lives of four of the American soldiers, while the fifth was killed later yesterday, according to ISAF statements.
Both attacks took place in southern Afghanistan, where the war is at its fiercest, ISAF said.
The deaths bring to 397 the toll of foreign soldiers killed in the war so far this year, compared with 520 for all of 2009.
An AFP tally based on that kept by the icasualties.org website puts the number of soldiers to have died since the Afghan insurgency began in 2001 at 1,965 - 1,205 of them were Americans.
IEDs are the main cause of foreign soldiers' deaths, according to military officials, who say the payload of the crude home-made bombs is rising as the Taliban insurgents adapt to the greater defences of the foreign forces.
The US and Nato have almost 150,000 troops in Afghanistan, with the surge of an extra 30,000 Americans ordered by US President Barack Obama almost fully deployed, most of them in the southern hotspots of Kandahar and Helmand.
Obama has said he wishes to start drawing down US forces in the middle of next year, and Britain, which has the second largest combat contingent in the country, is eager to pull out within five years.
Afghanistan's army and police are being trained by their international counterparts, with plans to reach a combined force of 300,000 by later this year, aiming for a deadline for taking over security of 2014.
President Hamid Karzai's pledge, made at his inauguration speech in November, when he began his second term as president, was reiterated at a conference in Kabul this week of his international supporters.
His promise that Afghan security forces would be competent enough to work alone to secure the country from the Taliban onslaught has been met with some scepticism that numbers are more important than the ability to meet targets.
Washington's top military officer, Admiral Mike Mullen, arrived in Islamabad yesterday amid US concerns about sanctuaries in Pakistan for extremist groups blamed for attacks on Afghan targets.
Speaking to reporters in New Delhi before leaving for Islamabad, Mullen described the Haqqani network, believed to be based in Pakistan's North Waziristan tribal district, as "the most lethal network" faced by US-led coalition in Afghanistan.
Pakistan has long faced charges that it provides safe havens for groups such as the Haqqani, which fund, staff, plan and carry out attacks in Afghanistan.
• Nato also said yesterday two American soldiers in Afghanistan have gone missing.
The missing soldiers had left their compound in Kabul late last Friday "and did not return", a statement from Nato's International Security Assistance Force (ISAF) said.
Their vehicle had been recovered, an official said, adding that ISAF was receiving conflicting reports about the fate of the two.
"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.
All reports were unsubstantiated, he said.
ISAF's statement said a road and air search had been launched.
A Taliban spokesman denied the insurgents were behind the disappearance of the soldiers.
Speaking to AFP by telephone from an undisclosed location, the Taliban's spokesman for eastern Afghanistan, Zabihullah Mujahid, said: "So far, we are not aware of it and cannot confirm this."
Kidnappings of foreign soldiers are rare in Afghanistan, where a nine-year insurgency has been escalating in recent months, particularly in the southern provinces of Helmand and Kandahar.
Most kidnappings in recent years have been by criminals for ransom, though targets identified as high value have in the past been sold on to insurgent groups, who then use them as political pawns.
The Taliban warned earlier this year they would target foreign military and government installations and staff, as well as Afghans working for them or for the Kabul government.