A major incident has been declared in the West Midlands after sodium cyanide was spilled into a canal, with the Walsall council warning of a potential serious health risk to anyone who has had direct physical contact with the water.

Walsall council said people must avoid an extended area of the canal and towpaths from the Walsall lock flight to the lock flights at Rushall, Ryders Green and Perry Barr.

In a statement, the council said it was notified of a spillage in Pleck by the Environment Agency on 12 August that had gone directly into the canal. The agency was testing the canal water for sodium cyanide and other chemicals in the affected area.

Ingesting cyanide salts, which can dissolve in water, releases cyanide into the body, according to Public Health England. Exposure to the chemical can cause headaches, nausea, dizziness, confusion, changes in heart rate and loss of consciousness, according to the agency.