A large police presence was spotted in the Glebe Park area of Lincoln.
Lincolnshire Police confirmed the emergency services were attending to a domestic incident.
One person told The Lincolnite police cars were speeding down in the Glebe Park area at around 1.15pm and a helicopter was seen in the Wolsey Way area.
Three unmarked cars and a van were also seen, as well as a dog unit and other police cars.
A spokesperson for Lincolnshire Police said it is a domestic issue and they are unable to release any further details.
They did not confirm details about the reported helicopter.