Part of the Upper Newtownards Road has been closed between the Knock traffic lights and Cabin Hill Park on Sunday afternoon.
A number of homes have been evacuated, with Stormont Presbyterian Church made available for those affected.
Police area the scene and diversions are in place.
Police are currently attending a security alert at Upper Newtownards Rd in East Belfast. Part of the road is closed, diversions are in place
More top news
Eleven years after her arrival at Animal Lifeline centre in Staffordshire, Maggie is still waiting for a new owner.
After 1995, rugby was triumphed as a symbol of post-apartheid South Africa, but has struggled to live up to the ideals of the new era.
A British violin teacher who shot himself while facing extradition over abuse claims would have faced 77 charges, police have said.