The assault, which Notts Police described as ‘serious’, happened at around 1am.
At this stage the victim’s injuries are not thought to be life threatening.
Churchgate car park in the town centre is still sealed off while the investigation continues. The cordon is expected to be lifted later this afternoon.
Officers are trawling CCTV footage of the area and making enquiries.
A red Ford Transit van has been recovered and is being examined, but no arrests have been made yet.
“Patrols have been increased in the area to provide reassurance,” said the spokesman.
“If you were in the Churchgate area at around 1am, saw a red van or any unusual or suspicious activity contact police on 101, quoting incident 111 of 8th February 2014, or call Crimestoppers anonymously on 0800 555 111.”