A teenager was ‘sprayed in the face with a noxious substance’ during a town-centre assault on Tuesday.
Lincolnshire Police are appealing for witnesses to the incident, which they say took place at about 4.20pm, in the Market Place, near the Ingram Memorial.
The 16 year-old male vitim required medical treatment after the substance resulted in irritation to the face.
Two juvenile males, aged 16 and 17, were arrested and later released on bail until January.
PC Christopher Lill is appealing for any witnesses, who were in the area at the time, and saw the assault.
Anyone with information call 101 and quoting incident number 304 of December 8, 2015.
Report crimes anonymously by contacting Crimestoppers on 0800 555 111.