Image caption The UK and Spain have been in dispute over fishing rights off Gibraltar, a UK territory which Spain also claims

Tensions over fishing rights around the British territory of Gibraltar have been raised, following an incident involving Gibraltarian police boats and British Royal Navy, and Spanish police.

It comes after several days of dispute in which Spanish police escorted Spanish fishing boats near the area.

The Gibraltar government says fishing with large nets there is illegal because of an environmental law.

Spain claims sovereignty over Gibraltar, a British colony since 1713.

Several Royal Gibraltar Police boats surrounded three Spanish fishing vessels on Wednesday night after they cast their nets near Gibraltar harbour, media reports say.

The UK's position on sovereignty has not changed and will not change Spokesperson, UK Foreign and Commonwealth Office

Gibraltarian news agency GBC News said several Spanish Guardia Civil boats appeared to be defending the fishermen, but were told to leave by the Gibraltarian police.

The Spanish boats reportedly left the area later, after a Royal Navy vessel arrived and told them again to depart.

Gibraltar's chief minister, Fabian Picardo, said the Gibraltarian government condemned what were "obviously carefully premeditated challenges to our indisputable sovereignty, jurisdiction and control of British Gibraltar Territorial Waters and our airspace" - according to GBC News.

'No negotiations'

A Foreign Office statement confirmed that Britain's minister for Europe, David Lidington, had met with Mr Picardo to discuss various issues, including the fishing dispute and recent incidents in British Gibraltar Territorial Waters.

"Mr Lidington reiterated that the UK's position on sovereignty has not changed and will not change", it said.

"The UK will never enter into arrangements under which the people of Gibraltar would pass under the sovereignty of another State against their wishes.

"Furthermore, the UK will not enter into a process of sovereignty negotiations with which Gibraltar is not content."

But Spanish Interior Minister Jorge Fernandez Diaz said Madrid would continue to dispatch police boats to protect Spanish fishermen in the area.

"We are not going to accept intimidations or humiliations," he told reporters.

"What the government is doing is defending the fishing rights of our fishermen."