Police officers arrested a 25-year-old in Drake Road, Bloxwich, on Tuesday after after a "small explosion" at a flat at around 4am.
West Midlands Police is continuing to investigate the incident, saying detectives from the Force Criminal Investigation Department are leading the probe.
Three people were treated for shock in the aftermath of the incident.
After checks by the fire service and a bomb squad, the property was declared safe.
West Midlands Police said counter-terror officers are not involved in the investigation.