(THE HAGUE, Netherlands) — Seven men were arrested Thursday in the Netherlands on suspicion of plotting a large-scale extremist attack that Dutch prosecutors said they think was foiled following a months-long investigation.

The national prosecutor’s office said in a statement that heavily armed police arrested the men in the towns of Arnhem, about 100 kilometers (62 miles) south of Amsterdam, and Weert in the southern Netherlands close to the borders of Germany and Belgium.

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

The suspects allegedly wanted to use bomb vests and assault rifles to do harm at the event, and planned to detonate a car bomb at another location, prosecutors said. An investigation of potential targets was continuing.

Prosecutors said the suspects ranged in age from 21 to 34. ..

The U.N. Human Rights Council voted Thursday to establish an international body that will collect evidence and prepare case files of alleged atrocities in Myanmar, where the military has been accused of committing genocide against the Rohingya Muslim minority.

Creation of the new body marks a major step toward criminal prosecution over the violence that caused more than 700,000 Rohingya to flee across the border into Bangladesh since August last year, many alleging army abuses such as arson, rape and murder.

The 47-member council voted 35 to three, with seven abstentions, to “establish an ongoing investigative mechanism to collect, consolidate, preserve and analyse evidence” of international crimes committed in Myanmar since 2011 and “prepare files… to facilitate and expedite fair and independent criminal proceedings.”

The resolution, jointly advanced by the Organization of Islamic Cooperation and the European Union, marks “an important step for justice,” Human Rights Watch Geneva d..