Afghan officials say suicide bombers have struck two police stations in the capital, Kabul, killing two officers.
Suicide bombers and gunmen launched apparent coordinated attacks on two Kabul police stations on Wednesday, with security forces still searching buildings for some of the assailants.
A series of loud explosions rocked the Afghan capital in the late morning and were quickly followed by volleys of gunfire as police engaged in fierce battles with militants.
At least two officers were killed and half a dozen civilians were wounded in the attacks, one of which was ongoing, police and health officials said, as the city braces for more violence in the coming days.
After an easing of attacks in Kabul in February and March, Taliban and Islamic State militants have stepped up assaults in the city in recent weeks.
IS claimed responsibility for the first attack on a police station in a heavily Shiite-populated neighbourhood in the city's west, which police spokesman Hashmatullah Estanakzai told AFP had ended.
Interior ministry spokesman Najib Danish said a suicide bomber blew himself up outside the station, triggering an intense gunfight.
"Two attackers were killed. Two policemen also lost their lives and two policemen are wounded," Estanakzai said.
Ariana TV footage showed a thick plume of black smoke rising into the sky while a photo posted on Twitter purportedly of the west Kabul police station showed a building on fire.
The second attack took place in front of a police station in Shar-e-Naw neighbourhood in downtown Kabul where a "search and clearing operation" was still under way.
An AFP correspondent near the scene of the second attack saw a body on the street by the police station and heard several gunshots. He also saw several terrified women running away from the scene.
A travel agency that handles Indian visa applications is located on the same street as the Shar-e-Naw police station. The Indian embassy and some of its consulates in Afghanistan have previously been targeted by the Taliban.
Health ministry spokesman Waheed Majroh said one person was killed in the west Kabul attack and six others wounded.
He had no further details on casualties.
There was no immediate claim of responsibility for the second of the attacks that come just over a week after twin blasts in Kabul killed 25 people, including AFP chief photographer Shah Marai and eight other journalists.
Those attacks were claimed by IS.
The Taliban recently launched their annual spring offensive, in an apparent rejection of a peace talks overture by the Afghan government.
Their Operation Al Khandaq will target US forces and "their intelligence agents" as well as their "internal supporters", a Taliban statement said on April 25.
Kabul has long been one of the deadliest places in Afghanistan for civilians.
A suicide bomber targeting a blood drive for victims of recent attacks blew himself up in a city park on Monday after being spotted by police, causing no other casualties.
On April 22, a suicide bomber detonated himself outside a voter registration centre in the city, killing 60 people and wounding more than 100.
That was among a series of attacks across the country in places where people were signing up to vote.
The Taliban and IS have made clear their intentions to disrupt the parliamentary and district council elections scheduled for October 20.
General John Nicholson, who leads US and NATO forces in Afghanistan, said previously that protecting Kabul was a priority for foreign troops.
But he acknowledge that preventing attacks would be challenging in the sprawling city that is poorly mapped and extremely porous.