British warship chased a Spanish customs vessel out of British territorial waters at Gibraltar, a spokesman for the British military command in the contested territory said Wednesday. The frigate HMS Argyll was leaving Gibraltar on Tuesday on deployment to the Middle East when it spotted the Spanish ship in British waters off the territory, the spokesman at the British military command said. "Argyll turned and followed the customs vessel round Europa Point and into the Bay where the customs vessel exited British Gibraltar's territorial waters," he said. The Spanish vessel, a large corvette-type vessel named "Fulmar", then sailed to the Spanish port of Algeciras on the other side of the bay, he added. It was the latest in a series of maritime face-offs in the waters off Gibraltar, which is strategically placed at the western entrance of the Mediterranean. In April Gibraltar police charged one of its boats was damaged in a clash with Spanish police vessels that illegally entered its waters in pursuit of alleged drug traffickers. Britain claims a strip of three nautical miles (5.5 kilometres) surrounding Gibraltar as its territorial waters. But Spain does not recognise any waters off Gibraltar as belonging to the territory apart from its ports. Spain ceded Gibraltar to Britain in 1713 under the Treaty of Utrecht but has long argued that it should be returned to Spanish sovereignty. Britain has said it will not renounce sovereignty against the wishes of Gibraltarians.