An Afghan policeman turned his weapon on fellow officers as they were sleeping in their quarters near a checkpoint in the country's south, killing 10, a provincial spokesman said Tuesday.

The Taliban quickly claimed responsibility for the incident, the latest so-called "insider attack" involving a soldier or a policeman.

The bodies were discovered at a checkpoint in Chinarto district on Tuesday, according to Dost Mohammad Nayab, the spokesman for the governor of Uruzgan province.

The shooter fled the scene after the attack late Monday, taking all the weapons and ammunition from the checkpoint, Nayab said.

"The police units have launched an operation to locate and arrest the shooter," he added.

Taliban spokesman Qari Yousaf Ahmadi said in a statement that the attacker was now with the Taliban.

Insider attacks have been common in Afghanistan, especially in remote areas where the Taliban have a strong presence. Taliban insurgents have been known to wear Afghan police or military uniforms when staging attacks on Afghan or foreign troops.

Last week, a policeman shot dead nine comrades at a checkpoint they were manning in Dehrawad district, also in Uruzgan province. On the same day, Jan. 18, another policeman killed four fellow security forces at a checkpoint in Lashkar Gah, the capital of southern Helmand province.

The Taliban have stepped up attacks on Afghan forces in recent months. The U.S. and NATO formally ended their combat mission at the end of 2014, leaving Afghan security forces in charge of public safety.

In a separate development, a senior Taliban figure announced his support for Mullah Akhtar Mansoor, who was appointed to succeed the group's founder and longtime leader Mullah Mohammad Omar after his death was announced last summer.

That announcement set off an internal conflict and raised questions about the future of the insurgent movement.

Mullah Hassan Rahmani, a senior Taliban figure who was the governor of the southern Kandahar province when the group ruled Afghanistan from 1996 to 2001, announced his support for Mansoor in a message sent to media on Tuesday. He had initially refused to accept Mansoor's leadership.

"I have dedicated my life to the prosperity of Islam and dreamed of a free Afghanistan," Rahmani said in the statement. "I have accepted Mullah Akhtar Mansoor as the leader of the Taliban from my heart."

Ahmadi, the Taliban spokesman, confirmed Rahmani's pledge of support.

Also Tuesday, Afghan security forces launched an operation in northern Baghlan province to drive insurgents from the area, said Jawed Basharat, spokesman for the provincial police chief.

A statement from the governor's office said at least 10 insurgents have been killed and one policeman has been wounded in Dand-e Ghori district.