JOHOR BARU - Twenty-seven passengers were left injured, three of them seriously, after an express bus rammed into a road divider and fell into a drain on Tuesday, Malaysian reports said.

The Straits Times understands that the bus was travelling from Ipoh to Singapore.

Singaporean Liu Tianyou and his wife Zheng Yufang, 56, who were returning from Ipoh after the Chinese New Year holiday, were among those hurt.

Mr Liu was slightly injured, while Madam Zheng has been hospitalised for observation after she hurt her ribs.

Batu Pahat district police official Din Ahmad was cited by The Star as saying the accident took place at the KM100.1 mark of Johor's Pagoh-Yong Peng stretch along the North-South Expressway. Other reports said the mishap happened at about 4.15am.

"The bus smashed against the road divider before going into the opposing northbound lane," Din said, according to The Star.

"The bus then plunged into the drain at the side of the road and toppled to its side," he said, adding that three were severely injured while 17 others suffered from minor injuries. They were sent to Hospital Sultanah Nora Ismail for treatment.

The official said the weather was "fine" at the time of accident.