Dutch authorities say seven men were arrested on September 27 in the Netherlands on suspicion of plotting a large-scale extremist attack.

The national prosecutor's office said in a statement that heavily armed police arrested the men in the towns of Arnhem, about 100 kilometers south of Amsterdam, and Weert in the southern Netherlands, close to the borders of Germany and Belgium.

The statement said the probe was triggered by intelligence suggesting the alleged ring leader, a 34-year-old man of Iraqi heritage, wanted to carry out an attack at the venue of a large event and cause multiple casualties.

The suspects allegedly wanted to use suicide vests and automatic rifles and planned to detonate a car bomb at another location, prosecutors said.

An investigation of potential targets is continuing.

Prosecutors said the suspects were aged from 21 to 34. Three of them, including the 34-year-old Iraqi, were previously convicted of attempting to travel overseas to join extremist groups.

The men were to be brought before an investigating judge on September 28 at a behind-closed-door hearing.

Based on reporting by AP and Reuters