LONDON, April 4 (Xinhua) -- A Spanish gunship on Tuesday made an "illegal incursion" into British waters off Gibraltar amid rising Brexit tensions over the territory, the Gibraltar government said.
"Illegal incursion into #British #Gibraltar Territorial Waters by Spanish Navy patrol ship Infanta Cristina this afternoon," said the local government in its twitter account alongside with a short video.
According to local media reports, the British Royal Navy HMS Scimitar chased the Infanta Christina out of British waters - ordering it to leave immediately, but the incident, the seventh of its kind this year, is likely to escalate already rising tensions over the sovereignty of the area.
"The Royal Navy challenges all unlawful maritime incursions into British Gibraltar territorial waters,"a British government spokesman said Tuesday, as cited by local daily Gibraltar Chronicle. "We back this up by making formal diplomatic protests to the Spanish government,"added the spokesman.
The armed ship sailed into British waters just hours after Spanish Foreign Minister Alfonso Dastis told Britain to "calm down" after form Tory Leader Lord Michael Howard said he believed the prime minister would "go to war" over the Rock.
A row has erupted after draft Brexit negotiating guidelines drawn up by the European Council identified future arrangements for Gibraltar as one of its 26 core principles.
The guidelines stated: "After the UK leaves the union, no agreement between the EU and the UK may apply to the territory of Gibraltar without agreement between Spain and the UK."
The row has become one of the early flashpoints in Brexit negotiations which started last week after British Prime Minister Theresa May triggered Article 50, the process for leaving the European Union, and spectacularly failing to make any mention of Gibraltar in the letter delivered to the EU.
That clause has potentially put Britain and Spain on a collision course over the future of this area.
May on Sunday gave assurances over Gibraltar in a telephone call with Chief Minister of Gibraltar Fabian Picardo.
An official spokesman for 10 Downing Street said: "The prime minister said we remain absolutely dedicated to working with Gibraltar for the best possible outcome on Brexit, and will continue to involve them fully in the process."
Gibraltar, located on the southern tip of the Iberian Peninsula at the entrance of the Mediterranean, was ceded to Britain as part of the Treaty of Utrecht in 1713. Spain has persistently sought to regain the tiny southern territory.