An attacker shouting "Allahu akbar" stabbed a Belgian policeman several times in the neck in central Brussels on Tuesday, prosecutors said.
The assailant, who wielded two kitchen knives during the incident outside the city's main police station, was then shot and wounded by two police officers, they said in a statement.
The man is under arrest and in critical condition in hospital. The policeman is also in hospital but did not suffer life-threatening injuries in the attack at around 5:am (0430 GMT).
"We have not yet established the subject's motives," the city prosecutors said. "Several witnesses heard him shout 'Allahu akbar' (God is greatest). The investigation will establish whether this is a terrorist act."