Hundreds of Taliban fighters have launched a brazen attack on the northeastern Afghan city of Kunduz, trading heavy fire with police and soldiers in their third attempt this year to capture the provincial capital.
The siege came a day after a bomb attack on a volleyball match killed 13 and the Islamic State group carried out co-ordinated strikes against police in the country's east, ending a brief lull in violence during the Muslim festival of Eid.
"The Taliban launched an attack on Kunduz city from several directions," Kunduz provincial police spokesman Sayed Sarwar Hussaini told AFP.
"So far 20 Taliban insurgents were killed in the fighting in different parts of Kunduz, and four Afghan security forces were confirmed wounded."
Earlier the Taliban had seized several security checkpoints near the city, an AFP journalist in Kunduz said, though it was unclear if they had held on to their gains.
The city's streets were deserted as residents barricaded themselves indoors.
"The situation is very bad. The fighting is particularly fierce in the southeastern area of the city," a Western NGO official told AFP.
"There are still a few people on the streets but far less than usual."
Taliban spokesman Zabihullah Mujahid claimed responsibility for the attacks, adding their fighters had overrun several checkpoints and killed 12 Afghan soldiers. The toll could not be verified.
The militants were also laying siege to all the city's checkpoints, police stations, and the governor's headquarters, Mujahid added.
The Taliban have been waging a bloody insurgency since a US-led invasion ousted them from power in late 2001, and have stepped up attacks during a summer offensive launched in late April against the Western-backed government in Kabul.
On Sunday (local time) 13 people were killed and 33 wounded at a volleyball match in the eastern province of Paktika, while IS fighters launched co-ordinated attacks on police checkpoints in the eastern province of Nangarhar.
The Taliban denied being behind the attack in Paktika, a volatile frontier region considered a stronghold of their allies the Haqqani network.