A 23-year-old woman has been arrested on suspicion of administering a noxious substance after staff and residents at a sheltered housing complex were taken ill.

West Midlands Police said yesterday 16 people had fallen ill with food-poisoning type symptoms at Goldfield Court, an extra care unit for the elderly in West Bromwich.

Four of the people were taken to hospital, where two continue to receive treatment.

The woman, who was arrested on Monday, has been released on police bail to a secure unit while investigations continue, a force spokeswoman said.

Further tests and inquiries are under way to determine the exact nature and cause of the illness, she added.