Police and Army bomb disposal officers are at the scene of the alert on North Queen Street.
AN ATO robot has been deployed to examine an object and the road has been closed.
The Westlink has been reduced to one lane northbound between Clifton Street and York Street.
The Clifton Street onslip is also closed.
The alert began in the early hours of Tuesday and North Queen St residents, living between the Brougham Street and Great George’s Street junctions, were asked to leave their homes.
Traffic is slow in the area and motorists are advised to leave more time for their journeys.
Southbound Westlink traffic has also been affected by a broken-down car.
The vehicle is blocking the inside lane, near the Clifton street onslip.