LONDON (AP) — Police in London arrested a man on suspicion of contaminating food in three supermarkets by injecting them with syringes.

Local authorities advised shoppers at the stores in the west London area of Hammersmith to throw away their purchases after the suspect was detained on Wednesday night.

Authorities have not identified how many items were tampered with or if the syringes had anything inside.

Officers were first called out at 7:40 p.m. for reports of a man shouting abuse at people in the street.

London’s Metropolitan Police Service said the suspect allegedly used “a number of needles” to inject into processed meat and microwaveable products at small branches of Sainsbury’s, Tesco and Waitrose on Fulham Palace Road.

He was arrested “on suspicion of contamination of goods with intention of causing public harm or anxiety,” the police department said.

The three stores remained closed Thursday. The Hammersmith and Fulham Council said an investigation was ongoing.

“Members of the public are advised as a precaution to dispose of any food items bought from these supermarkets yesterday evening,” the council said in a statement.