Danish police say they have arrested a fourth man suspected of assisting a gunman who killed two people in attacks in Copenhagen last month.

Spokesman Joergen Skov described the suspect as a "young man'' and said he would face a custody hearing Friday. He declined to comment further on Thursday's arrest and did not name the suspect.

On Feb. 14, Omar El-Hussein killed a bystander outside a free-speech seminar before spraying the entrance with 27 bullets. Hours later, the 22-year-old El-Hussein fatally shot a Jewish guard outside Copenhagen's main synagogue. Five officers were also wounded in the attacks. El-Hussein was later killed in a police shootout.

Three men are already in custody suspected of assisting El-Hussein. (AP)