U.S. coalition troops detained four suspected Al Qaeda members during a raid in eastern Afghanistan on Sunday, while a roadside bomb in the south killed a NATO service member, officials said.

The U.S.-led troops captured the four in the city of Khost, close to the border with Pakistan, the coalition said in a statement.

"The suspects are believed to be associated with an Al Qaeda leader who has been responsible for recruiting Kuwaiti and Pakistani extremists for fighting in Afghanistan, threatening to strengthen al-Qaida's presence, namely in the eastern provinces," the statement said.

The U.S. military did not identify the suspects or the leader mentioned.

Militants launched numerous coordinated attacks against government buildings and the main U.S. base in Khost this month. Militants operating in the area fall under the command of Sirajuddin Haqqani, an insurgent leader believed to be operating out of Pakistan's tribal areas. The area is considered the likely hiding place of Osama bin Laden.

Teams of Taliban have also hit government centers in Kabul, Kandahar and Helmand's capital in the last year, demonstrating increasing sophistication in their attacks. Military analysts have said such assaults are a result of training by Pakistani militants and al-Qaida fighters.

President Barack Obama has identified the elimination of militant sanctuaries in Pakistan as critical if America is to crush al-Qaida and turn around its faltering Afghan war effort.

In southern Afghanistan, meanwhile, a roadside bomb killed a NATO service member Saturday, the military alliance said in a statement.

It did not identify the victim's nationality. NATO follows a policy of waiting for the relevant country to announce the nationality of dead troops.

More than 40 countries contribute forces to the conflict in Afghanistan under NATO's banner. A number of nations have troops serving in the south, including Britain, the United States, Canada, Denmark and Australia.

Obama has ordered an additional 21,000 troops into Afghanistan, the majority of which will be heading south where the Taliban is strongest.