KABUL, Afghanistan - Two American soldiers were killed by a roadside bomb and a British soldier was shot dead on patrol Tuesday, raising the NATO death toll in Afghanistan to two dozen in little more than a week.

The bloodshed spiked ahead of a major NATO operation in the Taliban's southern heartland. U.S. commanders have warned of more casualties as the alliance gears up to clear Kandahar, the biggest city in Afghanistan's south and the former headquarters of the Taliban.

NATO announced the three deaths Tuesday without identifying nationalities. But U.S. and British authorities identified the nationalities of the victims, all of whom died in the south.

The deaths took NATO's death toll in June to 24, including 14 Americans, according to a count by the Associated Press based on official announcements.

Monday was the deadliest day of the year for the international force in Afghanistan with 10 deaths - seven Americans, two Australians, and a French Legionnaire.

They were killed in five insurgent attacks in the south and east of the country. Two civilian contractors training police, an American and a Nepalese, also died in a suicide attack Monday in Kandahar city.

Afghan officials said two other battles raged overnight between Afghan and NATO forces, in the provinces of Kandahar and Badghis in the northwest. No NATO casualties were reported.

The range of attacks served as a grim reminder that the insurgents can strike throughout the country - not simply in the south, which has become the focus of the U.S.-led campaign.

President Obama in December ordered 30,000 more U.S. troops to Afghanistan to try to stem the rise of the Taliban, which has bounced back since being ousted from power in the 2001 U.S.-led invasion.

In the northern city of Mazar-e-Sharif, about 1,000 people shouted "Death to America, Long live Islam!" and burned an effigy of the pope in an angry demonstration against alleged Christian proselytizing in Afghanistan.

Afghan authorities on May 31 suspended operations of Church World Service, based in Elkhart, Ind., and Norwegian Church Aid pending an investigation of allegations carried in an Afghan television report. Both charities deny spreading Christianity.

Mohammad Hashim Mayar, deputy director of the Afghan group that coordinates nongovernment organizations in the country, said officials at the intelligence service that is conducting the investigation told him Tuesday it was yet to be completed.

In Pakistan early Wednesday, extremists struck trucks carrying military vehicles for allied forces in Afghanistan, killing six people and wounding seven, police said.

The attack came at a truck stop on the main road leading to the Afghan border about six miles from Islamabad. The Pakistani capital is well-protected, so an attack so close to it is likely to cause Pakistanis particular unease.

Much of the fuel and other supplies for the U.S.-led force in landlocked Afghanistan are trucked through Pakistan after arriving on ships at the Arabian Sea port of Karachi.