British warships arrived in Gibraltar on Monday for scheduled exercises amid tensions with Spain over fishing around the British Mediterranean enclave.
Although British, Spanish and Gibraltarian authorities have said the navy's arrival at the British overseas territory is long-scheduled, some in Spain see it as provocative.
At about 0800 GMT the frigate HMS Westminster sailed into the port of Gibraltar flanked by two smaller ships.
It was followed an hour later by the auxiliary ship Lyme Bay, part of a task force of four warships and five other vessels that left Portsmouth and Plymouth about a week ago for exercises in the Mediterranean and the Gulf with various allies.
Gibraltar's creation of an artificial reef with concrete blocks, which Spanish fishermen say blocks their access to certain waters, has prompted Spain to toughen its border checks, leading to long queues for workers and tourists entering Gibraltar.
Spain claims the territory, population just 30,000, which it ceded to Britain by treaty 300 years ago.