Police line the parking lot of a train station in Chicago, the United States, Sept 2, 2024. This is in response to four people being killed in a shooting on a commuter train in Chicago, US media reported. [Photo/Xinhua]

WASHINGTON, Sept. 4, 2024 -- Four people were fatally shot on a commuter train in the Chicago area early Monday, and it appears the victims were attacked while sleeping in their seats, police reported Monday afternoon.

According to the Forest Park Police Department, a review of security footage showed that the victims seemed to be asleep, seated separately, and did not resist the attack. The shooting occurred in two separate train cars.

A suspect has been taken into custody, and a weapon was recovered. The motive is still unknown.

Forest Park is a village in Cook County, Illinois, and a suburb of Chicago.

Also on Labor Day, five people were shot in the afternoon when a suspect discharged a weapon into a crowd along the New York Caribbean Carnival parade route, according to police. Two people were critically wounded.

In Nashville, Tennessee, six people were hurt during a shooting at a bar parking lot early Monday morning.

Over 380 mass shootings have occurred in the United States in 2024 so far, according to the Gun Violence Archive, which defines a mass shooting as an incident in which four or more victims are shot or killed.