Gunmen take dozens hostage in eastern Afghan city of Jalalabad

Suspected Islamist militants stormed a government building in the eastern Afghan city of Jalalabad on Tuesday, taking dozens of people hostage after a suicide bomber blew himself up at the entrance gate, officials and witnesses said.

There was no immediate claim of responsibility, though a spate of deadly attacks on the city in recent weeks have been seen as a show of force by the Islamic State militant group.

According to one witness, a passerby named Obaidullah, the latest attack began when a black car with three occupants pulled up at the entrance to a building used by the department of refugee affairs, and a gunman got out firing around him.

One attacker blew himself at the gate and the two other gunmen entered the building, in an area close to shops and government offices, said Obaidullah.

A few minutes later, the car blew up, wounding a number of people in the street, he said.

"We saw several people wounded and helped to carry them away," Obaidullah said.

As security forces closed off the area, gunshots could be heard and a clouds of black smoke spiralled into the sky above the area.

Sohrab Qaderi, a member of the local provincial council, said around 40 people appeared to be caught inside the building, which caught fire in the initial stages of the attack.

One hostage had called the security services and told them that the attackers had ordered the people inside not to move, he said.

Provincial government spokesman Attaullah Khogyani said the attack happened during a meeting with NGOs working on refugee-related issues. The head of the department and several other people were taken to safety, he said.

Although it is unclear whether there is any direct connection, Islamic State attacks have picked up as hopes for peace talks between the government and the Taliban have grown in the wake of last month's three-day ceasefire.

The casualties add to a mounting toll in Afghanistan. On the other side of the country, in the western province of Farah, a roadside bomb hit a bus, killing as many as 11 people, officials said.