SINGAPORE - Two Singaporeans were killed and two others seriously injured on Monday night in a car crash across the border in Muar, Johor, after they lost control of their car on the North-South highway while headed toward Singapore.

The Singaporeans - Lee Ting Kok, 54, and Leong Ngiok Lan, 77 - were both seated in the front and were killed on the spot.

Two teenage girls - Lee Yan Yi, 18, and Lee Yan Xuan, 16 - were extricated from the wreck and sent to Batu Pahat Hospital for treatment.

The four Singaporeans were a family on their way back to Singapore after a holiday in the Malaysian capital, Kuala Lumpur.

The cause of the accident, which took place at about 7pm on Monday night, is still unknown, but the car had crashed into the road side divider and continued charging forward for about 150m before finally hitting a tree and overturning.