The attack in Jalalabad targeted the compound of the refugees and repatriations department.
A suicide bomb and gun attack by militants on an Afghan government building in Jalalabad on Tuesday killed at least 15 people, some burned "beyond recognition", officials said, the latest in a series of assaults on the eastern city.
On the other side of the country a roadside bomb apparently intended for security forces hit a passenger bus and killed 11 people, marking yet another bloody day for civilians who have borne the brunt of violence in Afghanistan.
The attack in Jalalabad targeted the compound of the refugees and repatriations department. It ended after more than five hours of intense fighting between militants and security forces, said Attaullah Khogyani, spokesman for the governor of Nangarhar province.
At least 15 people were killed and the same number were wounded, Khogyani said.
Provincial health director Najibullah Kamawal said some of the dead were "burned beyond recognition".
The raid began with a suicide attacker blowing up a bomb-laden car at the entrance as local representatives of foreign donors and agencies were meeting department employees inside the building.
"About 10 minutes before the end of the meeting we heard an explosion and then gunfire," a government official told media reporters.
"We looked down and saw two attackers entering the building. I and a number of other people at the meeting escaped to a corner on the top floor. I don't know what happened to the others."
The driver for one of the people at the meeting said he was on the third floor when the attack began.
"People started screaming and running around," he told AFP.
"I jumped from the third floor onto a wall and then into the lane."
Several people were taken hostage by the attackers, said Zabiullah Zmarary, a provincial council member.
"I saw a black Corolla car drop three armed men at the gate of the refugees and repatriations department," a witness told AFP.
Khogyani said the two attackers who stormed the compound were killed.
Security forces swarmed into the area, and a plume of thick black smoke rose into the sky above the compound.
The Taliban denied involvement in the incident in a WhatsApp message sent to journalists.
There was no immediate claim of responsibility for the attack, which comes three days after militants raided a midwife training centre in Jalalabad.
Meanwhile, in the western province of Farah on Tuesday the bomb which hit the bus killed at least 11 people and wounded 31.
"It was a bomb planted by the Taliban to hit security forces but... it got a passenger bus," Farah provincial police spokesman Muhibullah Muhib told reporters.
However, there was no immediate confirmation from the Taliban that they were responsible.
