Police arrested four people and seized bomb-making supplies during raids targeting suspected far-right extremists in the western German city of Cologne on Thursday.

Officers searched the homes of four men allegedly belonging to the far-right extremist scene. Police said the men were seeking to construct an explosive device.

The suspects were 36 to 53 years old. Special forces and explosives sniffer dogs took part in the raids.

Police said they found the basic supplies for building an explosive device, as well as firecrackers.

State criminal police are investigating.

The raids took place in the Cologne districts of Nippes, Holweide and Mülheim. Police also seized drugs, in sufficient quantity to form the basis of initial charges against the suspects.

A police spokesperson told local paper Kölner Stadt-Anzeiger: "There was a suspicion that someone was obtaining basic materials for the manufacture of IEDs, unconventional explosives and incendiary devices."

German Chancellor Olaf Scholz said on Wednesday that far-right extremism posed the greatest threat to German democracy.

aw/msh (AFP, dpa)