An explosion has occurred close to the Ministry of Defence in the Afghan capital Kabul, a department official has told Reuters.
Witnesses separately reported hearing a large blast to the news agency.
The incident comes a day after the US secretary of defence Chuck Hagel arrived in the country on a surprise visit.
More top news
A documentary about the brutal gang rape and murder of a woman on a Delhi bus in 2012 has been banned in India.
Scotland Yard are asking for the public's help to find the dangerous men who are wanted in Europe but are believed to be hiding in the UK.
A Bolton chemistry teacher is to be sentenced today after admitting terror offences - with police claiming he wanted to join Islamic State.