Belgium’s home affairs minister said that the government does not “have control of the situation in Molenbeek,” a working-class neighborhood of Brussels that has been linked to several terrorism plots in recent years.

Speaking on the VRT television channel on Sunday, the minister, Jan Jambon, said that the government would “step up efforts” to bring order to the area of the Belgian capital.

“I see that Mayor Françoise Schepmans is also asking our help, and that the local police chief is willing to cooperate,” Mr. Jambon said. “We should join forces and clean up the last bit that needs to be done; that’s really necessary.”

Prime Minister Charles Michel of Belgium said he was also concerned about jihadist networks in Molenbeek.

“I notice that each time there is a link with Molenbeek,” he said. “This is a gigantic problem. Apart from prevention, we should also focus more on repression.”

Belgian officials had said that the brother of one of the men suspected to be Paris attackers was arrested on Saturday in Molenbeek.