Armed officers and a police helicopter were deployed to Gainsborough after a group of teenagers, reportedly with weapons, committed racially aggravated, violent and sexual assaults overnight.
Four teenagers are in custody after allegedly carrying out the assaults.
Lincolnshire Police attended reports of incidents involving teenagers at the skate park, Heapham Road, Tennyson Street, Tower Street, Carlisle Street and North Street.
All of the reports were sent to the police on the evening of Tuesday, March 10.
The teenagers, who are aged 15, 16, 16 and 18, are all from the town and were also arrested on suspicion of assault and possession of an imitation firearm.
Police are also investigating reports that a machete and a firearm were used.
An ambulance took a woman to the hospital with an injury to her face, but the police have not revealed how serious the injuries are.
The force deployed local officers, a dog handler, a firearms officer and police helicopter.