Updated

KABUL, Afghanistan (AP) — A packed bus hit a roadside bomb in southern Afghanistan on Wednesday, killing 25 people aboard, as NATO announced another U.S. service member died in a rapidly rising monthly death toll.

The passenger bus was traveling in Nimroz province on a main highway toward the capital, Kabul, when it struck the explosive about 7 a.m., said Nazir Ahmad, a provincial government spokesman. Another 20 people were wounded, he said.

The explosion occurred near Delaram — a volatile area close to the borders of Helmand and Farah provinces.

Afghan President Hamid Karzai condemned the attack. "The criminals who did this are the enemies of Muslims," he said in a statement.

Also Wednesday, officials reported three more international service members were killed — two Italians and an American. The Italians died Wednesday in a roadside bombing north of Herat, the Italian Defense Ministry said. The American was killed Tuesday in the south, NATO said.

July is already one of the deadliest months for U.S. troops in the nearly nine-year Afghan war, with 59 service members killed so far. That's just shy of the 60 that died in June — the deadliest month for U.S. forces. Altogether, 82 NATO troops have died in July. In June, 103 NATO forces were killed.

The rising death toll comes as U.S. forces continue the search for a missing Navy sailor believed captured last week by Taliban forces when he and a colleague drove into an insurgent-held area of eastern Afghanistan. One of the sailors was killed in a firefight with militants, and the Taliban has said they seized the other.

NATO officials were unable to say what the two service members were doing in such a dangerous part of eastern Afghanistan.

The Navy identified the missing sailor as Petty Officer 3rd Class Jarod Newlove, a 25-year-old from the Seattle area. The Pentagon lists Newlove as "whereabouts unknown," and did not confirm he was captured.

The service member killed was Petty Officer 2nd Class Justin McNeley — a 30-year-old father of two from Wheatridge, Colorado. NATO recovered his body Sunday.

The sailors were instructors at a counterinsurgency school for Afghan security forces, according to senior military officials, who spoke on condition of anonymity because of the sensitivity of the case. The school was headquartered in Kabul and had classrooms outside the capital, but they were never assigned anywhere near where the body of the sailor was recovered, the officials said.

U.S. forces have pushed into southern Taliban strongholds in recent months and weeks in an attempt to squeeze insurgents out of the area where they have long functioned as a de-facto government. Along with the surge, attacks on military forces and Afghan supporters of the government have increased. Many civilians have also been killed or wounded in incidents such as Wednesday's bus bomb or caught up in the crossfire.

On Wednesday, an Afghan villager was killed by U.S. soldiers in the volatile Arghandab Valley, a strategic area near Kandahar City. An An Associated Press journalist who witnessed the shooting said soldiers approached a compound near where they had found a hidden bomb. Someone fired at the Americans, who shot back, killing a man who the troops said was carrying a rifle.

The villagers insisted that he wasn't Taliban and maintained they didn't hear gunfire although the AP journalist said bullets were flying near the troops.

On Monday, the Afghan government said 52 civilians, including women and children, died when a NATO rocket struck a village in southern Afghanistan last week — a report the international coalition has disputed.

Karzai's office said an investigation by Afghan intelligence officers determined a NATO rocket slammed into Rigi village in Helmand province, one of the most violent areas of the country.

The U.S.-led command also said an investigation was under way but reports of mass civilian casualties in Rigi were unfounded.

NATO said investigators determined alliance and Afghan troops came under attack Friday about 6 miles (10 kilometers) south of the village and responded with helicopter-borne strikes. Coalition forces reported six insurgents killed, including a Taliban commander.

Gulam Farooq, deputy commander for the Afghan National Army in the south, said he too sent investigators to Rigi. Eyewitnesses said 14 civilians from three families were killed in the fighting.

Abdul Whab, who lost seven members of his family, told Afghan army investigators his mother, holding a copy of the Quran, pleaded with insurgents to leave the area so civilians wouldn't be hurt, Farooq said.

Whab told investigators coalition fire killed 60 militants suspected of being foreign fighters, because they didn't speak the local Afghan language of Pashtu, said Farooq.

In central Uruzgan province, meanwhile, three Afghan soldiers were killed when their vehicle hit a roadside bomb Wednesday, said Gulab Khan, deputy provincial police chief.

German Army Brig. Gen. Josef Blotz told reporters Wednesday in Kabul the Taliban's senior leadership ordered the assassination of multiple tribal elders in an area of Uruzgan.

"This follows the kidnapping and execution of two tribal elders for cooperating with the coalition," he said, alleging recent attacks can be traced to instructions issued by Taliban leader Mullah Omar in June to attack anyone who supports the Afghan government.

During the past 90 days, 350 Taliban figures have been captured or killed by coalition forces, Blotz said.

Meanwhile, a NATO drone also went down in a Taliban-held area of northern Afghanistan because of mechanical problems, the alliance said in a statement. The craft, called a Luna UAV, contained no weapons or intelligence that could be exploited by enemy forces, NATO said.