A man stabbed a national guard officer in La Goulette, a suburb of the capital Tunis, the interior ministry said on Monday, the second such attack targeting the police in two weeks.
Police quickly arrested the suspect, the ministry said. The national guard officer was taken to a hospital and his condition was listed as stable.
The reasons of the attack are unknown.
Last month, a policeman died after a man fatally stabbed him on duty outside the Brazilian embassy in Tunis.