An explosion was on Wednesday reported near the Indian Consulate in Afghanistan's Jalalabad city, capital of the eastern Nangarhar province.
The blast, believed to be a suicide attack, occurred around noon (local time).
"We cannot provide details on casualties. There is fear of possible casualties, both civilian and security personnel," Xinhua quoted a police official as saying.
Government troops cordoned off the area shortly after the blast, keeping people away from the site fearing a second blast.
Several warning shots were also fired by the security force personnel.
Unofficial sources said the Indian Consulate office may have been the target of the attack in the city.
The nature of the blast might have been group attack or complex assault, involving several attackers, the official said.
The Iranian and the Pakistani consulate buildings are also located at the same place.
No group has yet claimed responsibility for the attack.