A knife attack at a supermarket in Boon Lay Shopping Centre yesterday afternoon left a 23-year-old man with injuries to his head and face.

Posts on online forums Reddit and HardwareZone showed long trails of blood staining the floor and shelves at the FairPrice outlet in the mall.

According to accounts posted online, at least two men were involved in the slashing incident, which left one of them with a deep diagonal cut across his forehead.

The police said they were alerted to the incident at 12.40pm.

A police spokesman said: "A 23-year-old man was attacked by another man with a knife. The 23-year-old man suffered injuries to his face and head and was conscious when conveyed to Ng Teng Fong General Hospital. Police investigations are ongoing."

An 18-year-old man has been arrested.

A Boon Lay resident in his 40s who was shopping at FairPrice at the time said he heard "loud shouting" from a few aisles down.

The man, who declined to be named, said he then saw a young man covered in blood when he rounded the supermarket aisle.

"It was so scary - there was blood everywhere," he said.

Another resident in her 60s, who was at FairPrice at around 12.50pm, said she saw three or four FairPrice staff attempting to help the bloodied man sit up.

"He was bleeding from his head and hands. It was really horrifying because the blood was dripping from his mouth too," said the resident, who wanted to be known as Madam Low.

The Straits Times understands that the FairPrice outlet was closed for several hours after the incident.

"We are aware of the incident that took place outside our store at Block 221 Boon Lay Place on Oct 7, 2020, at about 12.40pm," said a FairPrice spokesman.

"Our staff rendered immediate assistance and ensured that the safety of our shoppers was not compromised. Our store operations remain unaffected."