Updated

Prosecutors have dropped four of 11 counts against three activists accused of plotting Molotov cocktail attacks during the 2012 NATO summit in Chicago. But the most serious charges under Illinois terrorism laws remain.

The Cook County state's attorney office said Tuesday that prosecutors dropped two weapons counts and two arson-related counts. Opening statements are scheduled next week in the activists' trial.

The office didn't provide an explanation. But prosecutors sometimes shed counts to help streamline their presentation to jurors.

Brian Church, Jared Chase and Brent Vincent Betterly have all pleaded not guilty. Remaining counts include conspiracy to commit terrorism and providing material support for terrorism.

The trial is expected to focus on the state's rarely used terrorism statutes. Critics say they're unconstitutionally vague.