The bomb went off as soldiers and police officers were lined up to collect their salaries at the bank in Lashkar Gah, the capital of Helmand province, said Daoud Ahmadi, a provincial government spokesman. All of those killed were civilians, he said.

More than 20 people were wounded in the blast, including 10 soldiers and six police officers, Ahmadi said.

No one immediately claimed responsibility for the attack.

Less than three hours later, two explosions hit the south's largest city — Kandahar.

The first blast in Kandahar was a car bomb outside the city's main hospital that wounded seven people, said Kandahar police chief Gen. Abdul Raziq.

Soon after, a suicide car bomber blew up his vehicle near a police compound in the city, killing one civilian and wounding more than 20 people, said Zalmai Ayubi, a spokesman for the Kandahar provincial government.

Bombings are a regular occurrence in volatile southern Afghanistan, where insurgents use explosives to target government officials, NATO troops and Afghans working with both groups.

In the capital Kabul, meanwhile, a statement by President Hamid Karzai said six civilians, including four women, were killed in a NATO air strike on Friday in Logar province.

NATO earlier said it was investigating reports that civilians were killed in the strike.