Police have cordoned off Grand Parade in Skegness.
The road is closed between Harveys and the Pier, and officers are out in force.
A number of police, at least two patrol cars and an incident van are present on Grand Parade, and a fire ladder has also been observed.
Police have refused to release full details as to the nature of the incident, which began in the early hours of Monday morning.
But in a brief statement they said that officers were conducting searches after “an alarm activation” and described their presence as an “ongoing incident”.
They were also advising motorists to avoid Grand Parade if possible.
Eye witnesses have seen officers on roofs along the street, where torch beams have also been observed
- More on the incident as we get it.