A man’s thumb was bitten off by a fellow commuter on an MTR train during rush hour on Thursday morning. The incident took place at Mong Kok station as the pair fought over an alleged physical collision on a crowded train.

The two men were riding on a Tsuen Wan line service towards Central at around 9am.

Man, surnamed Tung, who got his right thumb bitten off. Photo: Apple Daily.

During the fight, a 54-year-old man surnamed Yu bit off part of the right thumb of a 64-year-old man surnamed Tung.

The pair were arrested on suspicion of fighting in public and were both hospitalised.

Mong Kok station. Photo: Apple Daily.

The thumb was later found in a train carriage in Central.

Tung will undergo an operation to reattach the thumb.

In 2016, passengers made an average of 5.2 million trips on the MTR per day with the Tsuen Wan operating at 103 per cent capacity during peak hours.