Police arrested 15 people in a dozen raids yesterday in Brussels and Vervier who are suspected of planning to attack police stations and kill officers; police uniforms, guns, explosives, and cash were seized during the raids. Terrorism charges were filed against five people. Some of the suspects had fought in Syria, and “most” were said to be Belgian. Two suspects were arrested in France, but Belgian authorities said the investigation had begun before last week’s terrorist attacks in Paris. The government announced new antiterrorism measures. Authorities estimate that 300-350 people have left Belgium to fight for jihadist groups in Syria and Iraq.