A woman armed with a knife went on the rampage on an overnight train in China, stabbing and wounding nine people as they slept, state media reported.

The attack, on a train in Heilongjiang province, is the latest in a wave of violent attacks that has shocked the country.

The woman went from berth to berth stabbing sleeping passengers until she was wrestled to the ground by other travellers, said Dongbei, a news website.