A courtroom at the ACT Magistrates Court was cleared after a man allegedly attempted to set fire to a flag  and made threats inside the building.

Police say officers were called to the court on Thursday morning following reports a 43-year-old Ainslie man was being disruptive.

It is alleged the man was verbally aggressive, made threats towards multiple people and attempted several times to set a flag alight.

As a precaution, the courtroom was cleared to ensure the safety of the public and court staff.

The man was removed from the room and spoken to by court staff and police before being escorted from the building.

He was arrested at his Ainslie home on Friday and charged with contempt of court, two counts of attempting to light an unauthorised fire, making demands accompanied by threats, offensive behaviour, and acting in a manner intended to cause public alarm.