KABUL: At least nine members of a local Afghan police force were killed when another policeman opened fire at them at a checkpoint in northern Balkh province, a provincial official said on Tuesday, the latest so-called "insider attack" in Afghanistan.
One policeman was wounded and three others were missing in the late Monday shooting in the district of Char Bolak, said Mohammadudin Khanjer, a police official.
According to Khanjer, the attacker was a policeman from another checkpoint in the same district.
He fled the scene, apparently to join the Taliban, and took with him all weapons from the checkpoint, Khanjer said.
The Taliban made no immediate comment on the attack but insurgents are active in Char Bolak and often attack Afghan security forces there.
In Kabul, the country's intelligence agency _ the National Directorate of Security _ said Tuesday that its officers have arrested at least 26 suspected members of the Islamic State group.
The agency said the militants had planned to target Shiite Muslims during the commemoration of Ashura this week, a major Shiite holiday.
A statement from the agency Tuesday said the militants, including a group leader, were nabbed in separate operations in Kabul.
The IS affiliate in Afghanistan has stepped up attacks on minority Shiites across the country and especially in Kabul.
An attack earlier this month in a Kabul Shiite neighborhood involving a twin bombing of a wrestling center killed at least 21 people, including two reporters, and wounded 89 others.
Afghan forces have struggled to combat both the Taliban and IS since the United States and NATO formally ended their combat mission in the country in 2014.