Armed Police have been called to a flat on Belgrave Place in the city this evening.
A large cordon has been put in place at Belgrave Place with the junction of Madeira Drive.
Officers were called just 11pm on Thursday evening.
Response officers and armed Police and a dog unit have both been seen at the location one resident has revealed that they have entered a property within the block after officers asked them to let them in and advised to say on their property.
It is understood to be drug gun related said a shocked bystander.
Officers controlling the cordon are advising people to keep back and for other resident to remain in their property whilst they deal with the incident
Sussex Police have been approached for comment