A number of homes have been evacuated after suspicious substances were found during a raid by anti-terror police.
Residents in six flats were asked to leave the area around Cheriton Gardens and Ormston Avenue in Horwich, near Bolton, Greater Manchester, following the raid at 10am on two houses in the area.
Police executed search warrants as part of an investigation into the possession and distribution of indecent images in Bolton, Greater Manchester Police (GMP) said.
A 38-year-old man from Horwich was arrested on suspicion of possession of indecent images and also on suspicion of offences under the Terrorism Act 2000, specifically possessing information likely to be useful for a person committing or preparing for acts of terrorism and offences under the Explosives Act.
The raids were supported by officers from the North West Counter Terrorism Unit.
Officers found some suspicious substances in the property on Cheriton Gardens and around six flats have been evacuated as a precaution while the substances are examined, the force said.
A cordon is in place and residents and motorists are being advised to avoid the area while emergency services deal with the scene.