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.

The American deaths this month include Petty Officer 2nd Class Justin McNeley from Kingman, Arizona, and Petty Officer 3rd Class Jarod Newlove, 25, from the Seattle area. They went missing last week in Logar province south of Kabul, and the Taliban announced they were holding one of the sailors.

McNeley’s body was recovered there Sunday, and Newlove’s body was pulled from a river Wednesday evening, Afghan officials said. The Taliban offered no explanation for Newlove’s death, but Afghan officials speculated he died of wounds suffered when the two were ambushed by the Taliban.

The discovery of Newlove’s body only deepened the mystery of the men’s disappearance nearly 60 miles (100 kilometers) from their base in Kabul. An investigation is under way, but with both sailors dead, U.S. authorities remain at a loss to explain what two junior enlisted men in noncombat jobs were doing driving alone in Logar – much of which is not under government control.

Newlove’s father, Joseph Newlove, told KOMO-TV in Seattle he too was baffled why his son had left the relative safety of Kabul.

“He’s never been out of that town. So why would he go out of that town? He wouldn’t have,” he said.

Senior military officials in Washington, who spoke on condition of anonymity because of the sensitivity of the case, said the sailors were never assigned anywhere near where their bodies were found.

A NATO official in Kabul shot down speculation the two were abducted in Kabul and driven to Logar – the same province where New York Times reporter David Rohde was kidnapped in 2008 while trying to make contact with a Taliban commander. Rohde and an Afghan colleague escaped in June 2009 after seven months in captivity, most spent in Taliban sanctuaries in Pakistan.

Samer Gul, chief of Logar’s Charkh district, said the two sailors, in a four-wheel drive armored SUV, were seen Friday a week ago by a guard working for the district chief’s office. The guard tried to flag down the vehicle, carrying a driver and a passenger, but it kept going, Gul said.

Gul said there is a well-paved road that leads into the Taliban area and suggested the Americans may have mistaken that for the main highway – which is much older and more dilapidated.

Elsewhere, violence continued today.

Four Afghan civilians were killed and three were injured when their vehicle was hit by a roadside bomb in Zabul province of southern Afghanistan, provincial spokesman Mohammed Jan Rasoolyar said. When police arrived at the scene, Taliban fighters opened fire. One insurgent was killed, the spokesman said.

In Kandahar, a candidate in September’s parliamentary election escaped assassination Friday when a bomb planted on a motorcycle exploded, city security chief Fazil Ahmad Sherzad said. The Interior Ministry said a woman and a child were killed and another child was wounded.