A Spanish ship has entered Gibraltar waters for the third time.

The P78 Cazadora, from the Spanish navy's Descubierta Class, deliberately entered the northern side of the Bay of Gibraltar at around 9am this morning.

The ship has now left the waters.

The news comes just two weeks after the Royal Navy HMS Scimitar intercepted the Infanta Cristina off the Gibraltar coast.

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A Spanish ship has entered Gibraltar waters for the third time in six weeks. The P78 Cazadora entered from the northern side of the Bay of Gibraltar

It is unknown if the ship has been chased out. The news comes just two weeks after the Royal Navy HMS Scimitar intercepted the Infanta Cristina off the Gibraltar coast

A UK Government Spokesperson said: 'The Royal Navy challenges all unlawful maritime incursions into British Gibraltar Territorial Waters (BGTW) – and did so again on this occasion.

'We back this up by making formal diplomatic protests to the Spanish government.

'We take these actions to defend our sovereignty over British Gibraltar Territorial Water.'

The HMS Scimitar has chased away the Infanta Cristina twice this month - on April 4 and April 13.

Even though it is the first time the P78 Cazadora has entered Gibraltar waters since the dispute over Article 50, it has done so before.

Disputes between Gibraltar and Spain over the waters are frequent but the latest comes after the territory became involved in Britain's exit from the European Union.

After Article 50 was triggered by Theresa May on March 29, Spain renewed calls to reclaim 'The Rock', despite overwhelming opposition from the people of Gibraltar.

The application of any EU-UK trade deal to Gibraltar had to be agreed between Britain and Spain, according to an EU draft position published earlier this month.

May issued a statement saying London was 'steadfast' in its commitment to the territory.

Disputes between Gibraltar and Spain over the waters are frequent but the latest comes after the territory took centre stage in the wrangling over Britain's exit from the European Union

May issued a statement saying London was 'steadfast' in its commitment to the territory. Former Conservative leader Michael Howard said the Prime Minister would be willing to go to war to protect the territory

At the start of April, former Conservative Leader Michael Howard backed Mrs May by saying she would be prepared to go to war to defend the territory.

Yesterday, Gibraltar's chief minister Fabian Picardo said he is confident the Prime Minister will support the territory.

He said: 'The next prime minister of the United Kingdom ... will continue to stand by the people of Gibraltar and continue to ensure that the sovereignty of Gibraltar is secure.

Spanish ships enter Gibraltar waters frequently when tensions between Britain and France escalate. The P78 Cazadora entered Gibraltar waters in October 2013

'The British people would judge very harshly a prime minister or any other minister in the British cabinet who at the last minute lets down the people of Gibraltar'.

During tensions between Britain and Spain in October 2013, the ship entered the territory's waters.

Defence Secretary Sir Michael Fallon told the BBC's Andrew Marr: 'We’re going to look after Gibraltar.

Yesterday, Gibraltar's chief minister Fabian Picardo said the Prime Minister would do all they could to protect the territory. He said: 'The next prime minister of the United Kingdom ... will continue to stand by the people of Gibraltar'

'Gibraltar is going to be protected all the way because the sovereignty cannot be changed without the agreement of the people of Gibraltar.'

Donald Tusk has also proposed a veto for Spain over any decisions that affect Gibraltar.

Gibraltar was captured by Britain in 1704 and ceded to Britain in 1713 under the treaty.

In a 2002 referendum, Gibraltarians rejected by 98 percent a proposal for joint British-Spanish sovereignty.