LONDON (AP) — Police in central England ordered half a dozen apartments evacuated briefly after finding what they called suspicious substances during a raid.

The evacuations followed a Wednesday morning raid at two houses in Horwich in Greater Manchester. Residents of the flats were allowed to return by midafternoon.

Greater Manchester Police said a 38-year-old man was arrested on suspicion of possessing indecent images and also on suspicion of possessing information likely to be useful for a person committing or preparing for acts of terrorism.

The raids were supported by officers from the North West Counter Terrorism Unit.