PARIS — Belgian counterterrorism police conducted raids across their nation Thursday, killing two suspected Islamist militants and disrupting an alleged plot to launch an attack that would have been the second instance of homegrown Islamist violence in Europe in eight days, officials said.
The dramatic police strikes coincided with heightened alerts across Europe in the wake of the deadly attacks last week in Paris by men claiming ties to al-Qaeda and the Islamic State.
European counterterrorism officials have been warning that their top security threat is the risk of attacks by their own citizens, radicalized by the conflict in Syria. The Belgian and French events, which did not appear to be directly tied to each other, underscored the dangers facing the Continent.
A spokesman for the Belgian national prosecutor’s office, Eric Van der Sypt, said that counterterrorism police raided a cell of returnees from Syria who were planning “a major imminent attack” in Belgium. Two of the suspects died in a shootout, and a third was severely wounded, he said.
Van der Sypt said the suspects, armed with what he described as weapons of war, opened fire on security forces who carried out the operation in the town of Verviers, about 75 miles east of Brussels.
Belgium raised its terror alert to its second-highest level as the operations continued.
Ten search warrants were served in all, Van der Sypt said.
The target of the alleged terrorist plot was not clear, although Brussels’s Le Soir newspaper reported that it might have been the police. Videos of the confrontation, which started at 6 p.m., near the height of rush hour, show explosions, gunfire and flames at a building near Verviers’ train station.
An investigation found “several people who we think are an operational cell, certain people who came back from Syria,” Van der Sypt said. “During the investigation, we found that this group was about to commit terrorist attacks in Belgium.”
There were no casualties among the security forces in the raid, he said.
Additional raids were carried out in the capital, Brussels, and near the suburb of Vilvoorde, which has become a haven for recruiters seeking to send fighters to Syria.
Belgium’s VRT radio and television network reported Thursday that Belgian security authorities had been monitoring the Verviers suspects for at least two weeks, before the attacks in Paris set off fears over homegrown Islamist militancy within Europe. Police recovered four Kalashnikov rifles, bomb-making materials and police uniforms from the Verviers raids, Le Soir reported.
The affiliation of the suspected terrorist cell in Verviers was not disclosed.
Earlier Thursday, prosecutors said they had detained a man in Belgium whom they suspected of supplying weapons to Amedy Coulibaly, a French citizen who killed four people and took hostages at that store in eastern Paris last week.
Coulibaly was killed that day in a police raid on the store that coincided with an assault on the hideout of two brothers who massacred 12 people in the offices of the satirical newspaper Charlie Hebdo in Paris.
The three gunmen killed a total of 17 people in last week’s violence in France, which began with the storming of the newspaper Jan. 7.
