A taxi driver was slashed across the face when he was forced to stop.
Cleveland Police said the incident happened at 2355 GMT on Friday when the 46-year-old taxi driver was travelling from Cowpen Bewley on Teesside.
He stopped when a man jumped into the road and a second man got into the car before demanding money and pulling a weapon when the driver refused.
But when the driver hand over £50 the man slashed him across the left cheek before running off.
Information appeal
Police said the driver was travelling to Cowpen social club at Billingham when the incident happened.
The two men made off in the direction of the Three Horseshoes Pub in Cowpen Bewley.
Both are described as white, of medium build, in their 20s and were wearing dark coloured hooded tops.
Police are appealing for anyone with information to contact them.