Airstrikes in Afghanistan's southern Helmand province have killed 21 civilians, including women and children, a lawmaker from the region said Sunday.

Mohammad Hashim Alkozai said 13 civilians were killed in one strike and eight in another. Both were carried out late Friday in the Sangin district, where heavy fighting is underway between NATO-backed Afghan forces and the Taliban. Alkozai said at least five other people were wounded in the airstrikes.

"Innocent people, women and children, are the only victims of the airstrikes," he said, adding that the military operations have stoked public anger.

Omer Zwak, the provincial governor's spokesman, said insurgents fired on Afghan forces from a civilian area. He confirmed that airstrikes had killed civilians but could not provide further information. He says an investigation has been launched.

Alkozai said he has raised concerns about civilian casualties in parliament and with government officials, but that they have taken no action.

On Sunday, hundreds of Afghans in Helmand protested against the deadly security offensives.

"This situation is no longer acceptable to us, and we are telling honorable President Mohammad Ashraf Ghani and NDS (secret service) head Masoum Stanikzai to put an end to these raids," Attaullah Afghan, chairman of the provincial council, told fellow protesters.

Afghan forces are struggling to combat the Taliban, who hold sway over nearly half the country and carry out daily attacks on security forces.

Elsewhere in Afghanistan, the Taliban killed at least eight Afghan police in an attack on a checkpoint in the northern Sari Pul province late Saturday, said Zabihullah Amani, the governor's spokesman. He said three other police were wounded in the gun battle, which lasted several hours.

The Taliban attacked an army checkpoint in the province late Friday, killing three soldiers and wounding four, Amani said.

In a separate development, the Afghan intelligence service said it had arrested three members of the Haqqani group, a Taliban faction believed to be based in Pakistan, in connection with two bombings in Kabul that killed and wounded dozens of people.

The National Directorate of Security said the three suspects confessed to taking part in a truck bombing near the German Embassy in May 2017 that killed at least 90 people, and a November 2018 attack that killed five security contractors, including a British national.

The NDS also said it had arrested a university professor and an imam in Kabul who had recruited hundreds of young people for the local Islamic State affiliate, sending them to the eastern Nangarhar province for training. It said the imam confessed that his own nephew had carried out a suicide bombing in Kabul.