Afghan roadside bombs kill four US soldiers

US soldiers have come increasingly under Taliban attack

Four US soldiers have been killed in two separate bomb attacks in eastern Afghanistan, Nato said.

In a press release, Nato said home-made bombs, one of the main weapons of the Taliban, were used in both the attacks. No other details were given.

The attacks come a day after seven US soldiers were killed in two bomb attacks in southern Afghanistan.

The deaths add to the rising trend of casualties for Nato's International Security Assistance Force (Isaf).

June and July were the worst months for foreign troop deaths since the US-led invasion of Afghanistan in late 2001.

Nearly 50 Americans have died in August alone. More than 350 Nato soldiers have been killed this year.

The Nato commander in Afghanistan, Gen David Petraeus, said international forces had reversed some of the gains the Taliban had made in recent years in the southern provinces of Kandahar and Helmand.

But, he added, the militants still retained the initiative in some parts of the country.