Two trains on the Tokyu Den-en-toshi Line collided on the tracks near Kajigaya Station in Kanagawa Prefecture late Sunday night, causing operators to halt service between Shibuya and Saginuma stations after one of the trains derailed. No one was injured.

The incident happened around 11 p.m. on Sunday when a train, heading toward Shibuya Station with 149 passengers, was about to enter Kajigaya Station in Kawasaki. It collided with an out-of-service train, resulting in the latter derailing.

As of Monday morning, the Den-en-toshi Line was operating only on the stretch between Saginuma and Chuo-rinkan stations with 40% of the usual number of trains. The Oimachi Line is also only running between Oimachi and Futako-tamagawa stations, with 30% of the usual amount.

It remains unclear when operations will resume for both lines but it is expected to take some time, the railway operator said.

“Ensuring transportation safety is the most important mission for railway operators,” Chief Cabinet Secretary Yoshimasa Hayashi said Monday morning. “The transport ministry will review the accident report submitted by Tokyu Railways and will provide necessary guidance to the company to ensure safe and stable railway operations.”

According to the transport ministry, a trainee driver operating the out-of-service train entered a detention line near the station when they received a signal designed to prevent overspeed, which is why the driver stopped the train before the designated position. Due to this, the train was sticking out on the tracks where the second train was approaching.

Although the driver of the second train tried to stop in time, it crashed into the rear of the out-of-service train, causing the latter to derail. The two trains still remained at the collision site as of Monday afternoon.

Two members of the Japan Transport Safety Board have been assigned to investigate the case.