Eight US soldiers have been killed in bomb attacks in southern Afghanistan, say Nato-led forces.

北约军队领导称，八名美国士兵死于阿富汗南部地区的炸弹袭击。

Foreign forces in Afghanistan are sustaining heavier casualties

An Afghan civilian¹ was also killed in what were called "multiple complex IED attacks" - or improvised²（即兴的） bombs.

The deaths make October the deadliest month for American forces in the eight-year war in Afghanistan.

On Monday, 11 soldiers were among 14 Americans killed in multiple air crashes. In total, 55 US troops have died in October, the Pentagon says.

Like many deaths in Afghanistan, Tuesday's bloodshed（流血，屠杀） was blamed on the improvised explosive devices (IEDs) that pose the biggest threat to foreign forces operating in the country.

"Additionally, several service members were wounded in these incidents and were transported to a regional medical facility for treatment," said a statement from the International Security Assistance Force (Isaf).

Military spokesmen said there had been two attacks on patrolling vehicles in the volatile³（不稳定的，挥发的） south of the country - one which killed seven soldiers and the Afghan civilian, and a second attack that killed one soldier.

But few other details were given, pending⁴ the notification of the soldiers' next-of-kin.

Also on Tuesday, the remains⁵ of three US crew were recovered from a US reconnaissance plane（侦察机） that disappeared on 13 October in Nuristan province in mountainous north-eastern Afghanistan.

Nato said the incident remained under investigation⁶, but hostile（敌意的，敌对的） action was not believed to be the cause of the crash.

Troops pressure

On Tuesday, the Washington Post newspaper reported that a senior US diplomat⁷ in Afghanistan had resigned, saying he had "lost understanding of and confidence in the strategic purposes of the United States' presence in Afghanistan".

State department employee Matthew Hoh, who was posted to Zabul province, said that the insurgency⁸ in some parts of Afghanistan arrived only after the US troops did.

US President Barack Obama is currently undertaking⁹ a review of American strategy in Afghanistan.

He is under pressure to reinforce the US military presence by tens of thousands of US troops - but many Americans are likely to oppose such a course in light of October's succession of deadly incidents, says the BBC's Andrew North in Afghanistan.

Mr Obama vowed¹⁰ on Monday that he would not rush the "solemn decision" to send more troops into battle, amid accusations¹¹（指责，谴责） by critics that he is dithering（颤动，抖动）.

Tuesday's attacks also come amid heightened（提高，加强） tension in Afghanistan in the run-up to the second round of a presidential election marred¹² by widespread fraud in favour of incumbent¹³ President Hamid Karzai.