French anti-terrorism police arrested four Islamist radicals on Wednesday on suspicion they were planning an imminent attack in central Paris, TF1 television said.

Three men and one women were arrested at dawn in Paris and the nearby northern suburb of Seine-Saint-Denis. Security forces had files on four of them for their Islamist ties, TF1 said on its web site.

Police also seized an unused cartridge for an automatic rifle and computer equipment, TF1 said.

Meanwhile, Belgian prosecutors on Wednesday named a 35-year-old Algerian as the man shot dead by police on Tuesday during a police raid on a Brussels apartment in the hunt for clues to bloody attacks in Paris last November.

Police found an Islamic State flag in the apartment used by Mohamed Belkaid and two others suspected of being with him after officers were met with a barrage of automatic weapons fire as they arrived to search the flat.

Belkaid, who was living in Belgium illegally and had a police record for theft but was not on security watchlists, was killed by a special forces sniper after a three-hour siege. A manhunt for the two other suspects continued on Wednesday.

The government held its alert status steady at Level Three, one step below the maximum.

The prosecutors said a radical Islamic text was found next to Belkaid's body and a cache of ammunition was also discovered. It was not clear if he had any links to the Paris suspects.

Two people detained overnight on suspicion of links to the shootout in the suburb of Forest were released without charge.

Investigators believe much of the planning and preparation for the Nov. 13 shooting and bombing rampage in Paris that killed 130 people was conducted in Brussels by young French and Belgian nationals, some of whom fought as militants in Syria.

Ten people are being held in Belgian custody on a variety of charges relating to the four-month investigation, though prime suspects, including Salah Abdeslam, a brother of one of the Paris suicide bombers, are suspected of having fled the country.

On Tuesday, six Belgian and French police officers arrived to search the flat and came under automatic fire through a door from at least two people barricaded inside. Four officers, one of them a Frenchwoman, were wounded, none very seriously.-Reuters