A man was assaulted when he tried to stop two thieves stealing a van from the driveway of his house.
The man went to investigate when he heard a noise last night outside his home on Glanford Crescent in Hilbaldstow, Brigg.
When he confronted the men he was hit with a blunt object, suffering minor head injuries.
Police are investigating the "nasty" incident and are appealing for witnesses.
The men fled the scene empty-handed in a white 4x4.
A spokeswoman for Humberside Police said: "We believe the vehicle may have been in the Brigg and surrounding area in the past few days and may be on false plates."