“So far, we have received 21 casualties – three were already dead on arrival,” tweeted Emergency, an Italian NGO which operates a hospital in Kabul.

A loud blast and gunfire were heard in Kabul near the guest house, a witness said.

Although the Taliban claim to have improved national security since storming back to power in August last year, there have been scores of bomb blasts and attacks – many claimed by the local chapter of the Islamic State group.

“It was a very loud explosion and then there was a lot of gunfire,” the witness told AFP, while local media also reported similar details.

Security officials were not immediately available to comment on the blast, which happened in Shahr-e-naw, one of Kabul’s main commercial areas.

There has been a significant number of Chinese business people visiting Afghanistan since the Taliban’s return to power, and Beijing maintains a full embassy even while not officially recognising the regime.