Brussels to remain on highest alert for a week

BRUSSELS — Citing a “serious and imminent” threat of attack, Belgium’s prime minister announced Monday that Brussels would remain at the highest alert level for at least one more week, maintaining security measures that have severely disrupted normal life in the capital.

In France, police said an explosive vest without a detonator was found by a street cleaner in a pile of rubble in the southern Paris suburb of Montrouge and was being analyzed by investigators. A police official said the vest contained bolts and the same type of explosives as those used in the Nov. 13 Paris attacks that claimed 130 lives and left hundreds wounded.

The device was found Monday in the same area where a cellphone belonging to fugitive suspect Salah Abdeslam was pinpointed by geolocation data on the day of the Paris attacks, two police officials said. The officials spoke on condition of anonymity because they were not authorized to discuss the investigation.

Belgian Prime Minister Charles Michel said Brussels, which houses the headquarters of the European Union and the North Atlantic Treaty Organization, faced a threat that required keeping the city at the highest alert level. The rest of the country would stay at the second-highest level.

Belgium’s crisis center said the alert level would change only if a significant breakthrough warranted it.

The increased security measures have virtually shut down the capital, with the subway system, many shops and schools remaining closed Monday.

Michel said that despite the continued high alert level, schools would reopen Wednesday, with parts of the subway system beginning to operate the same day. He did not say when the system would be in full operation again.

“We are very alert and call for caution,” Michel said.

Belgian authorities have not announced any details of their investigation into potential attacks nor have they released any information about four suspects who have been arrested and charged with terrorism-related offenses. These include one suspect who was arrested as part of a sweep that saw 21 people detained since Sunday night. Fifteen have been released.