THE HAGUE, Netherlands (AP) — A Dutch court convicted six men Thursday of plotting a large-scale jihadi attack on a public event and sentenced them to prison terms ranging from 10 to 17 years.

Rotterdam District Court said in a statement that the men were planning to open fire with AK-47 assault rifles at a festival and to detonate a car bomb in late 2018. They also wanted to wear explosive vests and detonate them when police arrived.

However, intelligence agencies tipped off police and an undercover operative was able to infiltrate the gang and ultimately thwart their preparations before any attack took place. The suspects were arrested by heavily armed police in September 2018.

The ring leader, a man of Iraqi descent, was sentenced to 17 years. The names of the defendants weren't released in line with Dutch privacy rules.

The gang “wanted to hit the civilian population and the police in the Netherlands with a bloody attack with a large number of innocent victims,” the court statement said. “Thanks to the timely intervention of Dutch government services, they were not able to carry out their plans.”