KABUL - Gunmen targeted Shiite pilgrims in Kabul late Tuesday, killing at least 14 people as they gathered to observe Ashura, officials said.

Some 36 people were wounded and at least one attacker killed, interior ministry spokesman Sediq Sediqqi said, adding that the assault was over.

Special forces had briefly entered the Karte Sakhi shrine near Kabul University to see if any more gunmen were sheltering inside, with police evacuating people from the area, officials said.

Of the 14 killed, 13 were civilians and one a police officer. Three police were among the wounded, Seddiqi said.

"A number of attackers have targeted people in Karte Sakhi shrine," said Kabul Police chief Abdul Rahman Rahimi.

"Police have evacuated dozens of people from the shrine. A number of civilians and police have been injured."

Police also said two grenades had been detonated during the attack.

No group has yet claimed responsibility for the assault, which President Ashraf Ghani condemned as a "clear sign of a crime against humanity".

Ghani vowed the government would use its "maximum capacity" to provide security during Ashura, which will be observed on Wednesday, and called on all Afghanistan's sects to "stand firmly against" the country's enemies.

The threat of attack targeting Shiites was considered particularly serious during Ashura, and many foreign embassies had restricted their staff's movements until the end of the week in Kabul.

The last attack on the Afghan Shiite minority, on July 23 in Kabul, killed 84 people and left 130 injured. It was claimed by the Islamic State organisation.

HUNDREDS OF AFGHAN TROOPS DEPLOYED IN LASHKAR GAH

Afghanistan has deployed hundreds of commandos backed by NATO air strikes in Lashkar Gah to flush out Taliban insurgents from the strategic city after the militants killed 14 people in a coordinated attack, officials said Tuesday.

The assault Monday marked the militants' latest attempt to seize the provincial capital of Helmand, underscoring unravelling security as the insurgents expand their foothold across the opium-rich province 15 years after the US invasion.

"More than 300 commandos... have been deployed to the city to prevent Taliban advancement," said Abdul Jabar Qahraman, government special envoy for security in Helmand.

Provincial spokesman Omar Zwak told AFP the commandos were sent from Kabul and neighbouring provinces to launch a "clearance operation" in Lashkar Gah after the attack, which killed 10 policemen and four others.

"Soon the security forces will clear the whole city from Taliban," Zwak said.

"US enablers are in the area and will support as needed. Yesterday there were two airstrikes in Helmand, both of these were in support of ANDSF (Afghan National Defense and Security Forces) strategic operations," a NATO spokesman told AFP Tuesday.

The Taliban have waged an insurgency against the western-backed Kabul government since being toppled from power by a US-led invasion in 2001. They have intensified attacks across the war-torn country in recent months, pressuring Afghan forces stretched on multiple fronts.

Around 30,000 people have been displaced in Helmand in recent weeks, mostly fleeing to Lashkar Gah, a city practically besieged, with roads from neighbouring districts heavily mined by the insurgents.

The intervention in Helmand has fuelled the perception that foreign powers are increasingly being drawn back into the conflict as Afghan forces struggle to rein in the Taliban.

Monday's early morning assault also underscored the Taliban's sustained push into urban centres, coming a week after the militants briefly stormed into Kunduz in the north before being repelled by Afghan forces.

The attack began with a car bombing in an attempt to break through the security belt in Lashkar Gah and enter the city, according to officials and local residents.

Mohammad Radmanish, a defence ministry spokesman, said security forces had managed to repel the attack and push back the insurgents, but feared they would return.

"We have enough forces on the ground now. Afghan airforce and NATO's air support is also helping our forces," he said.

On Saturday, General John Nicholson, the NATO military commander in Afghanistan, flew with the Afghan defence minister to Lashkar Gah to assure provincial elders that the city will not fall.

The Taliban effectively control or contest 10 of the 14 districts in the province, the deadliest for British and US troops over the last decade and blighted by a huge opium harvest that helps fund the insurgency.

In August Washington deployed some 100 troops to Lashkar Gah, the first major US deployment to the city since foreign forces withdrew in 2014.

In recent months, the militants have attempted to overrun other provincial capitals, from Kunduz and Baghlan in the north to Farah in the west, but Afghan forces have managed to repel the attacks.

Last week, the militants launched an assault on Kunduz in northern Afghanistan briefly hoisting their flag in the central square of the city, before they were flushed out by Afghan forces backed by NATO, a year after the city fell to them in their biggest victory since the 2001 invasion.

NATO officially ended its combat mission in December 2014, but US forces were granted greater powers in June to strike at the insurgents as President Barack Obama vowed a more aggressive campaign.