The Netherlands Police on Thursday said they had arrested seven men in connection with an alleged plot to carry out a “major terrorist attack” at a high-profile event, AFP reported. The men were looking to obtain AK-47s, hand grenades and raw materials to make bombs and were seeking firearms training.

The suspects belong to Arnhem and Rotterdam and surrounding villages. Police said two of them were convicted in the past for trying to travel to Iraq and Syria to fight for the Islamic State group.

“One of the men from Arnhem wanted to commit an attack with a group at a major event in the Netherlands and kill many victims, according to the Dutch Intelligence Service,” the public prosecutor’s office said in a statement. The prosecutors said the suspects expected to carry out twin attacks, including a car bombing, in the Netherlands at a large event “where there would be a lot of victims”.

The threat level in the country is at four out of a maximum five. “In a sense it is serious, but luckily it’s also good news – a terrorist cell that was plotting an attack has been taken down,” said Ferd Grapperhaus, the Dutch minister for justice and security, according to The Independent. “They weren’t so far that it was a danger to society, in the sense that it was nearly too late. But they were quite far in their preparations.”