Kuala Lumpur – Malaysian authorities have launched an investigation into a head-on collision involving two light rail transit (LRT) trains on Monday night that left 213 people injured, 47 of them seriously.

Malaysian media described the incident as the first major crash for the 23-year-old metro system.

AP reported that of the 213 injured, 47 were hospitalized for serious injuries and 166 had minor injuries. Pictures on social media after the Monday night collision showed bloodied passengers, some lying on the floor of the carriage strewn with blood and shattered glass.

Transport Minister Wee Ka Siong told local media that a metro train carrying 213 passengers collided with a vacant carriage on a test-run in a tunnel near the Petronas Towers, one of the world’s tallest twin towers.

“One carriage was travelling at 20 kilometers per hour (12.4 mph) and another at around 40 kilometers per hour (24.8 mph) when the collision happened. This caused a significant jolt that threw some passengers out of their seats,” he was quoted as saying.

Prime Minister Muhyiddin Yassin pledged a full investigation into the cause. Police said they suspected a miscommunication from the trains’ operation control center. The vacant carriage had a driver while the train with passengers was controlled by the operation center.

Some passengers were left in shock. Afiq Luqman Mohamad Baharudin, 27, told national Bernama news agency that many people were flung from their seats or fell on the floor. He said the train had stopped for 15 minutes just before the mishap.

“We had only moved for a few seconds when the crash happened and the impact was so strong that I suffered injuries to my head, left leg and chest,” he was quoted as saying.

The accident happened underground between the Kampung Baru and KLCC stations at 8.45pm.