Prosecutors say bombers had planned to hit France again

The militant cell behind bombings in Brussels had been plotting to hit France again after carrying out the Paris attacks but was forced to strike closer to home as police closed in, Belgian prosecutors said on Sunday.

Investigations into the Islamic State attacks in Paris in November which killed 130 people showed many of the perpetrators lived in Belgium, including surviving suspects who managed to evade police for more than four months.

Prime suspect Salah Abdeslam was arrested by police on March 18 after a shootout in the Belgian capital.

"Numerous elements in the investigation have shown that the terrorist group initially had the intention to strike in France again," Belgium's federal prosecutor said in a statement.

"Surprised by the speed of progress in the investigation, they took the decision to strike in Brussels," the prosecutor said.

Born and raised in Belgium to Moroccan-born parents, Abdeslam told a magistrate he planned to blow himself up at a sports stadium in Paris but backed out at the last minute.

His brother Brahim blew himself up at a Paris cafe.

Another man linked to the Paris attacks, Mohamed Abrini, was arrested in Brussels on Friday and he has admitted to being the "man in the hat" captured on video walking into Brussels airport alongside two suicide bombers.

Abrini, 31, has been charged with terrorist murders, prosecutors said.

Belgian intelligence and security forces had been criticised from abroad for not doing more to dismantle the militant cell, because of its links to the Paris attacks, though as of Friday all known suspects were either in detention or dead.

Belgium maintained its second highest threat level, however, on Sunday with Prime Minister Charles Michel saying his government would remain alert.

Another main suspect who was seen alongside the suicide bomber in the Brussels metro and identified by prosecutors as Osama K was also arrested on Friday in the Belgian capital.

Osama K, 28, widely named by media as Swedish national Osama Krayem, was filmed buying the bags used to carry the Brussels bombs.

Like Abrini, his fingerprints were found in an apartment used as a bomb factory and safe house for the attackers.

As with other suspects in both the Paris and Brussels attacks, police believe Krayem returned last summer from fighting with Islamic State in Syria aboard refugee boats reaching Greek islands