Updated

A NATO airstrike killed at least 25 suspected insurgents in eastern Afghanistan on Saturday, while violence elsewhere left 22 civilians dead in a wave of attacks days before the White House issues a review of U.S. war strategy, officials said.

A NATO force on patrol called for air support after coming under threat from insurgents in the Nari district of Kunar province, which has been the scene of heavy fighting along the Pakistani border. NATO said more than 25 militants were killed in the airstrike.

The coalition said another NATO unit in the Dara Pech district of Kunar killed an unspecified number of insurgents after coming under fire from small arms and rocket-propelled grenades.

Also in the east, about 500 people gathered Saturday in Paktia province, shouting "Death to Americans!" amid local reports that a NATO operation killed seven members of a private security company.

NATO said it was investigating the shootout, which occurred after coalition forces detained a suspected insurgent and tried to clear the area. Coalition forces then shot a man who approached them armed with an assault rifle.

"Multiple other armed individuals then engaged the force, which resulted in a total of seven individuals killed," NATO said in a statement. "The security force takes civilian casualty allegations seriously and is currently accessing who the individuals were, why they were armed and why they were in that area at that time of the morning."

Heavy fighting continues in the east even though the main focus of the war is in the south where NATO forces have pushed deeper into Taliban strongholds in Helmand and Kandahar provinces.

A car bomb exploded Saturday outside of police headquarters in Kandahar, wounding at least six people and blowing out the windows of buildings up to a mile (a kilometer and a half) away, officials said.

Two civilians and four police officers were wounded, said Zalmai Ayubi, a spokesman for the governor of Kandahar province.

Azar Jan, a police officer who was standing guard across the street from the police headquarters, said he noticed an empty, silver car parked on the street moments before the blast.

"As I was turning around, the explosion happened," Jan said, his bleeding head wrapped in a bandage.

In neighboring Helmand province on Friday, a roadside bomb hit a pickup truck carrying villagers in the Khan Neshin district, killing 15 civilians, Daoud Ahmadi, spokesman for the provincial governor, said Saturday.

Pressured in the south, the Taliban have opened new fronts in northern Afghanistan, where on Saturday a suicide bomber blew up a stolen police car packed with explosives. Five Afghan soldiers and nine civilians were wounded in the blast, which targeted an army checkpoint in Chahar Dara district.

Muhbobullah Sayedi, the spokesman for the governor of Kunduz province, said the force of the blast destroyed several nearby homes. The only person killed was the suicide bomber.

The Taliban claimed responsibility for the attack in a text message sent to the media.