Several bomb explosions shook different provinces of Afghanistan on Sunday, claiming lives of 11 persons including four U.S. soldiers, officials said.

"Four U.S. service members were killed in an improvised explosive device attack today," the U.S. military said in a press release.

"The service members were traveling in an up-armored, high- mobility, multipurpose wheeled vehicle in the Pech Valley, Kunar Province, when the incident occurred. The patrol was conducting route-clearance operations to keep the road open to civilian and military traffic," it added.

On Sunday morning, a bloody suicide bomb attack against Chairman of the Upper House Mujaddadi in the capital Kabul claimed four persons' lives including the attacker, and injured three others. The chairman was slightly injured in his hands.

Afghan President Hamid Karzai strongly condemned the attack and said the attack on Mujaddedi is "an attack on Afghans' independence, an attack against the Afghan voice, an attack against peace in Afghanistan."

On the same day, two bombs exploded in the southern Helmand province.

"This noon the vehicle full of Afghan police was exploded in a remote control bomb in Dishu district. One police was killed, two others were injured. These police are in charge of the eradication of poppy land in the province," Gen. Mohammad Ayob, the deputy provincial police chief of Helmand, told Xinhua.

Another official in Helmand said an explosion in Khannishin district claimed lives of two civilians and injured another one.

These explosions, according to the official, happened on the same day with the visit of U.S. ambassador to the province.

As the former stronghold of Taliban militants, Helmand has become the hotspot of the militancy. The NATO-led ISAF ( International Security Assistance Force) forces have decided to deploy about 6,000 more troops in Afghanistan especially in the southern area.

The first ISAF additional troops of about 150 British soldiers arrived in the troubled Helmand in the middle of February.

In another bomb explosion in the central Ghazni province Sunday targeting the Afghan National Army (ANA) soldiers, the vehicle of ANA was damaged, but fortunately no casualty among the soldiers, Abdul Rahman Sarjang, the provincial police chief, said.

Taliban militants, who vowed to drive out all the foreign troops, have intensified attacks since the beginning of this year. Till now more than 100 persons including 11 U.S. soldiers and two Canadian troops have been killed in the Taliban-linked militancy.

Source: Xinhua