Afghan soldiers move the bodies of victims from the scene of a suicide car bomb attack in Lashkar Gah in Afghanistan’s Helmand province on Feb. 11. (Noor Mohammad/AFP/Getty Images)

A suicide bomber detonated a vehicle laden with explosives outside a bank in Afghanistan’s Helmand province Saturday, killing soldiers on their way to pick up their salaries and civilians, the latest incident in spreading violence in the country.

At least 20 people, including both army troops and civilians, were wounded in the strike that happened outside a branch of the New Kabul Bank in Lashkar Gah, the provincial capital of restive Helmand province.

The chief spokesman for the Defense Ministry, Dawlat Waziri, in Kabul said five of the 12 killed were soldiers. A Health Ministry official said seven civilians also perished in the attack.

No group has yet claimed responsibility for the attack, part of spiraling violence that has hit various parts of Afghanistan in recent harsh days of winter, a season when fighting usually subsides in the country.

Helmand is the hub of Afghanistan’s illegal drug industry and part of the main bastion of Taliban insurgents. The United States has pledged to send several hundred extra troops in the spring, when violence usually increases.

The militants have unleashed several attacks in the province with their focus on Sangin ­district in the past few weeks, prompting airstrikes by the NATO-led Resolute Support ­mission forces.

When contacted, the head of the provincial council, Karim ­Attal, a spokesman for the army in Helmand, said they had received reports of civilian deaths in at least two such air attacks in two different villages of Sangin on Thursday night.

“We had 22 civilians, including women, children, young and ­elderly people killed in the air attacks,” Haji Daud, a tribal chief from Sangin said by phone.

“Thirteen of them were from one family and nine from another one, and they lived not far from the district center,” Daud said.

He said both heads of the two families were ordinary farmers, and he knew them well.

The Taliban had taken shelter in the mosque that was next door to the house of one of the farmers, named Feda Mohammad, Daud said.

“The Taliban use some private houses as their shelter, and this attack was not the first one and won’t be the last one here,” Daud said. “We are used to this and are under pressure from both sides [the Taliban, the Afghan government and foreign troops].”

The U.N. said it was also aware of the civilian deaths from the airstrikes, apparently the first one in Afghanistan since Donald Trump became U.S. president in January.

The Resolute Support forces confirmed conducting air attacks to defend Afghan forces on the ground.

“As with all claims of civilian casualties, we will investigate them to determine the facts and whether civilians were hurt or killed as a result of our operations,” Brig. Gen. Charles Cleveland, a spokesman for the coalition, said in response to an email.

The United Nations last week said the number of airstrikes by Afghan and coalition forces had nearly doubled in 2016, compared with the previous year. It also said nearly two-thirds of 3,500 civilian deaths were caused mostly by the Taliban’s expanding violence.