An armed Spanish gunboat has been ordered to leave British waters off Gibraltar for a second time, officials in the territory say.
On Thursday morning, patrol boat Infanta Cristina was ordered to exit the area by the Royal Navy unit stationed in the small British overseas territory – home to just over 30,000 people.
A UK Government spokesman told Sky News: "The Royal Navy challenges all unlawful maritime incursions into British Gibraltar Territorial Waters - and did so again on this occasion."
A tweet by the government of Gibraltar added: "Another Illegal incursion into British Gibraltar Territorial Waters by Spanish Navy ship Infanta Cristina today."
The Infanta Cristina was involved in a similar incident last Tuesday, amid heightened tensions over the Rock due to Brexit.
Tensions increased after an EU document suggested that Spain would be given a veto on post-Brexit agreements governing Gibraltar.
Since then Prime Minister Theresa May has offered reassurance that the UK remains "steadfastly committed" to the Rock.
Former Tory leader Michael Howard even suggested that Mrs May would go to war to defend the sovereignty of Gibraltar, leading Spanish foreign minister Alfonso Dastis to tell the UK not to "lose tempers" over the situation.
Spain has a long-standing territorial claim on Gibraltar, which has been held by the UK since 1713.