Cleveland Police are investigating after beach cleaners discovered what could be a grenade at Seaton Carew beach.
Bomb disposal teams from Catterick Garrison are on the way to the scene.
More top news
Chancellor George Osborne will seek to reassure financial markets on Monday morning following Britain's decision to leave the EU.
Eight crew members had to be rescued from a fishing boat after it started sinking a mile off the coast of Sunderland.
Drivers travelling north or southbound on the A1 near Newcastle and Gateshead are advised to expect delays until Wednesday morning.