Gunmen stormed a guesthouse in the Afghan capital today as it was hosting a party for foreigners.
An eyewitness said several dozen people, including Americans, had been taken hostage.
Details about exactly how many people were being held at the Park Palace Hotel in Kabul remained unclear into the night, as sporadic gunfire echoed around the guesthouse in a central neighbourhood which is home to United Nations compounds and a foreign-run hospital.
Two explosions were also heard and four ambulances arrived at the scene.
Amin Habi, a US citizen from Los Angeles, told the Associated Press that a party was going on at the hotel to honour a Canadian when the gunmen stormed the guesthouse. He said as many as 40 people, including foreigners and US citizens, could still be inside the hotel.
Amar Sinha, India’s ambassador to Afghanistan, said he believed at least six people still held inside were Indian citizens. Indian Prime Minister Narendra Modi’s Twitter account said he was “concerned about the situation (and) I pray for everyone’s safety”.
Police officers earlier freed some 20 people trapped in the guesthouse, but others remained inside, said Zia Massoud, an Afghan government official. He said at least one of them was wounded.
The hotel has both guest rooms for visitors and a residential area for those who live full time in Kabul, including foreign aid workers.
No-one immediately claimed responsibility for the attack, though the Taliban have attacked guesthouses before in Kabul.
Earlier today, gunmen killed 12 people and injured another 12 in an attack on a government compound in the city of Lashkar Gah, the capital of Helmand province, authorities said.
Afghan security forces have been struggling to fend off Taliban attacks since US and Nato forces formally concluded their combat mission at the end of last year.