BRUSSELS, Belgium - Authorities announced Tuesday that they had arrested two men and seized military-type uniforms and Islamic State propaganda in connection with a suspected plot to unleash holiday-season attacks against police, soldiers and celebrated locations in Brussels.

The attacks under preparation "were the same style as those perpetrated in Paris Nov. 13," in which 130 people were killed and hundreds injured by suicide bombers and gunmen equipped with Kalashnikov-style assault rifles, according to an internal document from Belgian state security services cited by RTBF French-language television. Those lethal actions were claimed by the Islamic State.

The two suspects were arrested following searches Sunday and Monday in the Brussels area, the eastern Liege region and Flemish Brabant, the Belgian Federal Prosecutor's Office said in a statement.

During the searches, no weapons or explosives were found, but military-type training uniforms, IS propaganda material and computer equipment were impounded and are being examined, the prosecutor's office said.

It said the case was unrelated to the brazen and bloody extremist actions in Paris a month and a half ago but that the investigation, which is continuing, has revealed a "threat of serious attacks that would target several emblematic places in Brussels and be committed during the end-of-year holidays."

An official close to the investigation told the Associated Press that targets included the Belgian capital's cobblestoned main square, thronged between Christmas and New Year's with shoppers and strollers, as well as a police headquarters in an adjacent street.

"On the Grand Place, there are a lot of people, as well as soldiers and police who are patrolling, as well as a police station nearby," said the official, who spoke on condition of anonymity because he was not authorized by the judge leading the investigation to make statements.

As of Tuesday, police and soldiers in Brussels are being ordered to take precautions to ensure their own safety, Benoit Ramacker, spokesman for the Belgian government's Crisis Center, said.

Police and army patrols were greatly beefed up in Brussels following the Paris attacks, and Ramacker said a new official threat assessment conducted Monday after the searches and arrests, concluded officers and troops deployed to protect Brussels have become targets of choice themselves.