The bloodshed comes as the Taliban and government negotiators engage in peace talks to end the nearly two-decade war.
Two members of an Afghan militia opened fire on their colleagues in western Herat province, killing 12 in what police described as an “insider attack”.
Herat police spokesman Abdul Ahad Walizada said on Saturday the attackers fled with the slain militiamen’s weapons and ammunition, adding Afghan government forces regained control of the area.
A Taliban spokesman, Yousuf Ahmadi, in a tweet claimed responsibility for the attack, which took place late on Friday.
Meanwhile, a sticky bomb attached to an armoured police Land Cruiser SUV exploded on Saturday in the western part of the capital, Kabul, killing two policemen and wounding another, Kabul police spokesman Ferdaws Faramarz said.
Faramarz did not specify the identities of the casualties. However, two members of the Afghan police force, speaking on condition of anonymity because they were not authorised to brief the media, said Kabul’s deputy police chief Mawlana Bayan was wounded in the attack.
No group immediately claimed responsibility for the bombing in Kabul.
In southern Helmand province, a suicide car bomber targeted a police compound late on Friday, killing one policeman and wounding two others, provincial police spokesman Zaman Hamdard said.
The attack took place in Lashkar Gah district on the highway between Helmand and the city of Kandahar. No one immediately claimed responsibility.
The armed group ISIL (ISIS) has taken credit for multiple attacks in the capital in recent months, including on educational institutions that killed 50 people, most of them students.
ISIL has claimed responsibility for rocket attacks in December targeting the major US base in Afghanistan. There were no casualties.
Frustration and fear
The violence comes as representatives of the Taliban and the Afghan government earlier this month resumed peace talks in Qatar.
However, the negotiations were off to a slow start while the armed group continues attacks on Afghan government forces, but has kept a promise not to attack American and NATO troops.
The talks are aimed at ending decades of relentless conflict. Frustration and fear have grown over the recent spike in violence and both sides blame one another.
Doubts have grown recently over the US-Taliban deal brokered by outgoing President Donald Trump’s administration.
That accord was signed last February. Under the deal, an accelerated withdrawal of US troops ordered by Trump means just 2,500 American soldiers will still be in Afghanistan when President-elect Joe Biden takes office on January 20.