Armed police detained a man after he became “aggressive” inside Manchester’s Polish Consulate.
Officers were called when two Polish nationals were asked to leave the building on Portland Street by security at 10:40 BST on Thursday, said a spokesman for the consulate.
One of the men left before police “pacified and arrested” the other man, the spokesman added.
Greater Manchester Police said it was trying to trace the second man.
The spokesman for the consulate said the two men “began to behave suspiciously” after arriving for a pre-arranged passport visit.
One of the men turned aggressive when he was asked to leave the building.