KABUL, Afghanistan - Nine NATO service members were killed yesterday in Afghanistan, including seven U.S. troops among eight who died when a powerful bomb exploded in a field where they were patrolling on foot, officials said.

Two Afghan policemen also died and two others were wounded in the explosion in the mountainous Shorabak district of Kandahar province, 12 miles from the Pakistan border, said Gen. Abdul Raziq, chief of the Afghan border police in the province.

"Two months ago, we cleared this area of terrorists, but still they are active there," Raziq said.

In Washington, meanwhile, war-weary lawmakers sent the strongest message yet to President Obama to end the war in Afghanistan as the commander in chief decides how many U.S. troops to withdraw this summer.

A measure requiring an accelerated timetable for pulling out the 100,000 troops from Afghanistan and an exit strategy for the nearly 10-year-old conflict secured 204 votes in the House, falling just short of passage but boosting the hopes of its surprised proponents.

"It sends a strong signal to the president that the U.S. House of Representatives and the American people want change," Rep. Jim McGovern, D-Mass., said shortly after the vote.

Obama will begin drawing down some of the troops in July, with all combat forces due out by 2014. McGovern and others fear that the initial reduction will be a token cut of some 5,000, numbers they argue fail to reflect that Osama bin Laden is gone and the United States can't afford spending $10 billion a month on the war.

An Associated Press-GfK poll earlier this month found 59 percent of Americans oppose the war and 37 percent favor it, with significant support for Obama's plan to start removing troops this summer.