British and Gibraltar officials say several Spanish police vessels and a customs helicopter illegally entered and violated the territorial waters and airspace of the tiny British territory of Gibraltar on the southwestern tip of Spain.

Britain's Foreign Office Minister Hugo Swire said Spanish vessels "repeatedly entered" the area on Sunday without properly notifying Gibraltarian authorities.

He said although the incursions were believed to be part of the pursuit of a suspected drug-smuggling speedboat, the actions were unlawful.

Gibraltar Chief Minister Fabian Picardo said Spain's chase, which included the customs helicopter flying low over his territory, were a display of "bravado" that backfired by allowing one suspected drug smuggler to escape, although two others, both Spaniards, were arrested.

Spanish authorities didn't immediately comment on the accusations.