Police secure an area in Brussels after arrests on April 8, 2016, of suspects linked to the attacks in the Belgian capital. (Geert Vanden Wijngaert/AP)

The Belgian federal prosecutor announced Tuesday that two more suspects have been charged in connection with last month’s terrorist attacks on the Brussels airport and subway system.

Prosecutors said the men — initially identified only as Ibrahim F., born in 1988, and Samil F., born in 1984 — were linked to the rental of an apartment in Brussels that appeared to serve as a safe house before the March 22 attacks that killed 32 people.

Investigators suspect that Khalid el-Bakraoui, 27, may have left the apartment before he detonated a suicide bomb on a subway train at the Maelbeek station, near the headquarters of the European Union. Earlier, twin suicide blasts struck Brussels Airport.

In recent weeks, Belgian authorities have made a series of arrests linked to a Brussels-based cell that planned the attacks in the Belgian capital and a deadly rampage in November in Paris that killed 130. Both assaults have been claimed by the Islamic State.

Also Tuesday, Belgian authorities detained three suspects outside Brussels in connection with the Paris attacks. According to the Belgian federal prosecutor, a judge will decide Wednesday whether to continue holding the suspects.

After Salah Abdeslam, 26, an alleged architect of the Paris attacks, was arrested in the Brussels neighborhood of Molenbeek last month, ties between the Paris and Brussels operations have become increasingly clear.

The assaults, the deadliest on French and Belgian soil since World War II, were both ultimately the work of a terrorist cell rooted in French-speaking Europe. The Paris rampage was largely planned from Brussels, where many of the suspects were raised. Likewise, several perpetrators of the Brussels attacks last month were involved in the earlier assault on the French capital, investigators have said.

A key suspect arrested Friday, Mohamed Abrini, 31, the “man in the hat” seen in surveillance video before the Brussels Airport blasts, was also spotted by cameras driving one of the alleged Paris attackers across the French-Belgian border before the Nov. 13 attacks in the French capital.

On Sunday, prosecutors said the terrorist cell — a web of predominantly young, European-born men quietly radicalized within Europe — initially planned a second assault in France but chose to act in Brussels, believing they were about to be snared by an intensifying investigation.

Belgian authorities have not released any specific information on the apparently abandoned French attack. A representative of the Belgian federal prosecutor did not respond to repeated requests for comment.

Late Tuesday, Dutch military police sealed off part of Amsterdam’s Schiphol Airport for hours after arresting a man for suspicious behavior. Explosives experts checked his luggage but found nothing dangerous, the Associated Press reported, citing police.