Four Dutch Moroccans have been arrested in connection with a plot to attack the Turkish consulate in Rotterdam, the public prosecution department said on Monday.

The four have been held on terrorism and related charges. Two are brothers aged 26 and 29 from Oudenbosch. The third is a 37-year-old man from Roosendaal and the fourth, who is 39, was arrested in Essen in Belgium.

The men were picked up after they were heard plotting to attack the consulate on a recording made by the AIVD security service in connection with another case, the public prosecution department said.

The police raided homes in in Oudenbosch, Roosendaal, Essen and Antwerpen as part of the investigation but found no weapons or explosives, police said. They did find a marijuana plantation with 100 plants at the home in Roosendaal.

The three arrested in the Netherlands will be in court for a remand hearing later this week. The man arrested in Belgium faces extradition.

The recording which led to the arrests was made in connection with another case in which a man in Rotterdam was jailed for four years after a Kalashnikov rifle, ammunition and a large amount of illegal fireworks were found in a storage box in Rotterdam last year.