Afghan militants attack military hospital 'dressed as doctors'

Afghan militants dressed as doctors have stormed the country's largest military hospital, officials said, as growing insecurity besets the war-battered country.

No group immediately claimed responsibility for the ongoing assault on the Sardar Daud Khan hospital, but it comes as the Taliban ramp up attacks even before the official start of their annual spring offensive.

At least two people were so far reported killed and 12 others wounded, the health ministry said around two hours after the raid began, with medical staff trapped in the facility posting desperate messages for help on social media.

"Attackers are inside the hospital. Pray for us," a hospital staff member wrote on Facebook.

Hospital administrators told AFP three gunmen wearing white laboratory coats were on the loose after a suicide bomber on foot blew himself up at the backdoor entrance, sparking chaos inside the 400-bed facility.

"I saw one of the attackers, armed with an AK-47 and dressed as doctor, shooting at patients and guards on the third floor," hospital nurse Abdul Qadeer told AFP. 

"They shot my friend but I managed to flee... I had to jump over the barbed wire to escape."

At least two other loud explosions - including what the defense ministry called a car bomb in the hospital's parking lot - were heard as Afghan special forces launched a clearance operation to rein in the attackers.

"Three attackers armed with AK-47s and grenades entered the building. Our commandos are chasing them," ministry spokesman Dawlat Waziri told AFP around four hours after the first explosion.

"One of them has been killed, but two others are still resisting on the sixth and seventh floors of the building. We have evacuated all the patients.

Afghanistan's warring parties, including government forces, have repeatedly targeted medical facilities, decimating Afghanistan's fragile health system and preventing conflict-displaced civilians from accessing lifesaving care.

"This is a criminal act. Nothing can justify an attack on hospitals," Afghan Chief Executive Abdullah Abdullah said of the latest attack. 

"We will never forgive these criminals. Unfortunately, this attack has resulted in some casualties. The attackers entered the backdoor disguised as doctors."

In an ambiguous statement, Taliban spokesman Zabihullah Mujahid said he could neither confirm nor deny that the insurgents were behind the attack. The militant group is known to distance itself from attacks that result in high civilian casualties.

The assault comes just a week after 16 people were killed in simultaneous Taliban suicide assaults on two security compounds in Kabul.

Dozens of others were wounded as a suicide car bomber struck an Afghan police precinct in western Kabul and a five-hour gun battle ensued after another attacker snuck in, sending clouds of smoke billowing into the sky.

In the second attack, a suicide bomber blew himself up at the gates of an Afghan intelligence agency branch in eastern Kabul.

The growing violence underscores rising insecurity in Afghanistan over the resurgent Taliban.

The country is bracing for an intense fighting season in the spring as the government's repeated bids to launch peace negotiations with the Taliban have failed.

Afghan forces, already beset by record casualties, desertions and non-existent "ghost soldiers" on the payrolls, have been struggling to rein in the Taliban since US-led NATO troops ended their combat mission in December 2014.