Some were seen arguing with police but were not shouting slogans or holding protest signs.

At least 50 police cars surrounded the ministry, and three men were seen by a Reuters witness being put into police cars.

"We have seen at least three or four police vehicles taking people away," said an activist there who declined to be named.

"Security have arrested around 15 people, they tried to go into the ministry to go and ask for the freedom of their loved ones."

Dozens of men in traditional white robes and red headdresses gathered outside while a large number of police and security forces watched.