A U.S. Air Force door gunner waits as a wounded soldier is loaded onto a helicopter Thursday during a rescue mission in the Arghandab Valley, Kandahar province, southern Afghanistan. The July death toll for U.S. troops in Afghanistan reached 63, making it the deadliest month for American forces in the nearly 9-year war.

KABUL, Afghanistan — Three U.S. troops died in blasts in Afghanistan, bringing the death toll for July to at least 63 and surpassing the previous month's record as the deadliest for American forces in the nearly 9-year-old war.

In Kabul, police fired weapons into the air today to disperse a crowd of angry Afghans who shouted "death to America," hurled stones and set fire to two vehicles after an SUV was involved in a traffic accident that killed four Afghans on the main airport road, according to the capital's criminal investigations chief, Abdul Ghaafar Sayedzada.

SUVs are often associated with foreigners, but it remained unclear who caused the accident because the occupants fled the scene. Sayedzada said two foreigners' vehicles at the scene were burned by the crowd.

A fatal traffic accident caused by a U.S. military convoy in 2006 triggered an anti-American riot in Kabul that left at least 14 people dead and dozens injured.

The three U.S. service members died in two separate blasts in southern Afghanistan on Thursday, a NATO statement said today. It gave no nationalities, but U.S. officials said all three were Americans. The officials spoke on condition of anonymity pending notification of kin.

U.S. and NATO commanders had warned casualties would rise as the international military force ramps up the war against the Taliban, especially in their southern strongholds in Helmand and Kandahar provinces. President Barack Obama ordered 30,000 reinforcements to Afghanistan last December in a bid to turn back a resurgent Taliban.

British and Afghan troops launched a new offensive today in the Sayedebad area of Helmand to try to deny insurgents a base from which to launch attacks in Nad Ali and Marjah, the British military announced. Coalition and Afghan troops have sought to solidify control of Marjah after overrunning the poppy-farming community five months ago.

In Kabul, a crowd threw stones and set fire to an SUV after a traffic accident today in which two Afghans were killed and two were injured, according to traffic official Abdul Saboor. SUVs are associated with foreigners, but Saboor said the occupants of the vehicle fled the scene.

The tally of 63 American service member deaths in July is based on military reports compiled by The Associated Press. June had been the deadliest month for both the U.S. and the overall NATO-led force. A total of 104 international service members died last month, including 60 Americans.