KABUL, Afghanistan - Three international coalition service members were killed in the south of Afghanistan, while U.S. and Afghan forces stepped up operations in the east against a Taliban faction linked to al Qaeda, arresting several key militants, military officials said Friday.

Britain's Ministry of Defence said one British soldier was killed Friday by small-arms fire in the Sangin district of Helmand province. Another serviceman who was injured Tuesday in an incident involving a helicopter at a patrol base in the Nahri Sarraj district of Helmand died Thursday at a hospital in Britain, it said.

NATO also reported the death of a third coalition service member after an insurgent attack Friday in southern Afghanistan. NATO did not disclose the nationality of the service member or details about the death.

In the east, NATO said a raid on Thursday in the Manduzai district of Khost province led to the capture of a deputy commander of the Haqqani group who had been supplying weapons to other members of the network. The commander was not identified but NATO said he was among "several" Haqqani group members rounded up in the raid.

Another Haqqani weapons supplier, who also was not named, was picked up Wednesday in Paktiya province, NATO said in a statement. It said he had been involved in smuggling weapons, ammunition and bomb materials from Pakistan to fighters in Afghanistan.

The U.S. considers the Haqqani group, led by Jalaluddin Haqqani and his son Sirajuddin, as one of the most dangerous Taliban groups because of its links to al Qaeda.

The group is suspected of playing a major role in the Dec. 30 bombing of a CIA base in Khost as well as a series of attacks in the capital of Kabul. It is based in the western border area of Pakistan, where U.S. forces cannot operate on the ground.

So far Pakistani authorities have resisted U.S. calls to launch a ground operation against the Haqqani network, saying its forces are overstretched fighting the Pakistani Taliban and other militants that have staged attacks inside Pakistan.