Belgian authorities have raised the terror alert in Brussels to the maximum (level 4) and have canceled major entertainment events for fears of an imminent, multi-pronged jihadist attack on the city, similar to those of November 13 in Paris.

“The increase in the alert level is due to the risk of attacks by individuals with weapons and explosives, possibly in multiple locations,” Belgian Prime Minister Charles Michel said in a press conference. He stated that the risk is based on “precise information,” but gave no further details.

The possible targets are shopping centers, public transportation, and events with large crowds. Michel said, “It is a threat of attacks committed in various places by multiple individuals.”

The Belgian National Crisis Center (OCAM) has spoken of a “serious threat” in a statement released by the country’s Ministry of the Interior.

Shortly after midnight, a series of dramatic security measures went into effect. Four subway lines in Brussels will be closed until Monday. The matches of the two major soccer series have been postponed. Citizens have been asked to avoid “places with high concentrations of people: concerts, railway stations, airports, public transport and shopping centers.”

The main theaters have been closed and the concerts suspended, including the much-anticipated francophone icon Johnny Hallyday, who was to perform in the Palais 12 concert hall. Post offices, swimming pools, and the largest shopping centers in Brussels have also been closed.

The government statement also asks the population to “facilitate security checks” and “not to contribute to spreading rumors, following only the official information from the local authorities and the police.”

Belgian Interior Minister Jan Jambon has called on police to conduct door-to-door searches in the Molenbeek district of Brussels, a known center of Islamist activity.

“The local administration should knock on every door and ask who really lives there,” he said in an interview with Flemish newspaper Nieuwsblad, noting that “of the 130 fighters who have returned from Syria to Belgium, 85 are living in Molenbeek.”

“It is unacceptable that we do not know who is in the territory of the municipality,” he said. “Right now there are apartments in which two people are officially registered, but in which ten are living.”

Follow Thomas D. Williams on Twitter @tdwilliamsrome.