A woman was killed and three other customers injured in a multiple stabbing incident at a Beijing supermarket on Monday, the capital's police said.

The woman, surnamed Liu, died in hospital after she was stabbed in the chest with a knife by a man in a Carrefour supermarket at Maliandao, Xicheng district, on Monday around noon.

The three other victims, including a 2-year-old boy who was seriously injured, have been hospitalized.

The suspect, a 50-year-old Beijing resident surnamed Wang, allegedly attacked the customers on the second floor of the Carrefour supermarket and was arrested at the scene, the Beijing Public Security Bureau said.

The boy was taken to the Intensive Care Unit of Beijing Children's Hospital at about 1 pm and underwent an almost four-hour operation.

Two friends of the boy's mother denied previous reports the boy's spleen had been removed, but said the knife pierced his stomach and his bowels had been seriously wounded. The boy was with his grandmother in the supermarket when he was attacked.

A 12-year-old boy who was stabbed in the back and a 24-year-old man who was stabbed in his torso were sent to Xuanwu Hospital for treatment, as was the woman who died.

Wang was reported to have bought a knife before beginning his attack, but police did not confirm that. The case is under investigation and the police declined to give more details.

Two police vehicles were parked near the supermarket and the store's door was closed when a China Daily reporter arrived at the scene.

The supermarket was closed to the public, and an officer, who declined to be identified, said the store would reopen on Tuesday.

An eyewitness named Xu, who runs a teashop near Carrefour, said, "Twenty minutes after the attack, three ambulances and one fire engine rushed to the store, and police immediately evacuated customers."

A customer, named Xie, in his 60s, said he was afraid to go to the store in the future.

"I may not go to the market in the near future considering such a dangerous attack happened," he said. "But the store is the biggest one in the neighborhood, so it's inconvenient."

Dai Peng, director of the criminal investigation department of the People's Public Security University of China, said security guards in large markets should be on alert after the attack and police officers should strengthen patrols.

"Supermarket security guards must be trained to deal with emergencies," he said. "Meanwhile, more police officers should be dispatched to ensure the security of big stores."

In addition, stores must install more cameras, aiming to find people acting suspiciously before events occur, he said.

He added that public places, such as stores and shopping malls, should arrange more workers to patrol on weekends and evenings.

Shen Jiahui and Wang Qing-yun contributed to this story.

caoyin@chinadaily.com.cn