BUENOS AIRES (Reuters) – Argentina protested to Britain on Saturday over a plan to carry out military tests in the Falkland Islands, stoking tensions that have increased over oil exploration in the disputed archipelago.

Deputy Foreign Minister Alberto D’Alotto said a letter of protest had been sent to the British ambassador in Buenos Aires over the exercises, which he said would involve firing missiles. He gave no further details.

“The Argentine government expresses its formal and energetic protest to this planned military exercise and demands the British government refrain from carrying it out,” D’Alotto said, reading from the letter.

He said the plan, which Britain informed Argentina about last week, was “an unacceptable provocation.”

President Cristina Fernandez condemned the plan via her Twitter account, saying it represented “a militarization of the South Atlantic.”

Nearly 30 years after the two countries fought a war over control of the British-ruled islands, tensions have increased this year because Argentina is angry British firms are searching for oil and gas in the seas around them.

In 1982, Britain sent a naval force and thousands of troops to reclaim the islands after Argentine forces occupied them. About 650 Argentine and 255 British troops died in the 10-week conflict.

Britain has a permanent military presence on the islands, called Las Malvinas in Argentina, and maintains a force of 1,076 troops and four ships in the region.

(Reporting by Magdalena Morales and Helen Popper; editing by Todd Eastham)