Citing a spokesman for the Afghan Interir Ministry, media reports say four inmates were killed and 33 people, including 20 police officers, were wounded in a prison riot that broke out at Pul-e-Charkhi Prison on May 14.

The clash reportedly began after the police began searching some cells at the prison. 

“Attorney General Office and Ministry of Interior Affairs had ordered a search of Special Narcotics Blocks of Pul-e-Charkhi Prison.  Four buildings were searched in morning.  But later violence broke out at midday during the search of remaining buildings after a group of prisoners attacked police, injuring 10 police officers," spokesman Nasrat Rahimi told Xinhua.

The police personnel reportedly fired on the air as the inmates tried to grab police forces' weapons during the clashes, he said, adding as a result of violence four inmates were killed and 13 prisoners and another 10 police were wounded.

The riot was brought under control in the afternoon, Rahimi added.

He said that an investigation has been initiated into the incident and details will be shared with the media soon.

Pul-e-Charkhi Prison, also known as the Afghan National Detention Facility, is the largest prison in Afghanistan.  It holds up to 5,000 inmates and is located east of Kabul.  Construction of the jail began in the 1970s and was completed during the 1980s.  The prison has been renovated in recent years by the help of the United States Army Corps of Engineers.