An explosion and ongoing gunfire were reported inside a military hospital in the Afghan capital, Kabul, officials said.
Defence ministry officials said the blast occurred at the front gate of the Sardar Daud Khan hospital in the Wazir Akbar Khan area in the centre of the city on Wednesday.
Dawlat Waziri, spokesman for the defence ministry, told Al Jazeera English Chanel that a number of fighters entered the hospital, the largest of its kind in the Afghan capital.
“Our security forces are on location fighting the attackers but they are also being careful to not cause any casualties. It’s a difficult situation,” Waziri said.
A hospital employee told Reuters news agency that he saw one gunman, dressed in a white doctor’s coat, take out a concealed AK-47 assault rifle and open fire, killing at least one patient and one hospital worker.
The Wazir Akbar Khan area of central Kabul is heavily guarded and houses several government offices and foreign embassies.
No group immediately claimed responsibility for the ongoing assault.
The attack comes 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.