Britain and Argentina's longstanding dispute over the Falklands escalated Thursday as Buenos Aires took legal action against companies exploring for oil off the islands and the countries summoned each other's ambassadors for a dressing-down.
The animosity between the two capitals, which fought a brief, bloody war over the South Atlantic islands in 1982, has intensified in recent years with the discovery of significant oil deposits offshore.
Adding to the bad blood in recent weeks, Britain has announced plans to beef up its defenses on the islands because of "continuous intimidation" from Argentina, while Argentine media reports have denounced British spying aimed at blocking the South American country's efforts to win sovereignty.
In the latest throwdown, the Argentine government said it had taken legal action in a local court against three British and two US companies for "carrying out exploration activities for fossil fuels on the Argentine continental shelf without obtaining the corresponding authorization."
The companies listed in the complaint are British firms Rockhopper Exploration, Premier Oil and Falkland Oil and Gas Limited and US firms Noble Energy and Edison International.
Argentina said the companies had sent a semi-submersible rig to explore for oil in a basin 200 kilometers (120 miles) off the islands' north coast, in what it described as areas "subjected to the illegitimate British occupation."
It also warned the rig's owner, Greece-based firm Ocean Rig, that it could face "legal consequences" over the drilling.
The court case came after Britain summoned Argentine Ambassador Alicia Castro on Wednesday to say it "object(s) strongly" to her and President Cristina Kirchner's recent statements on the Falklands, which Argentina calls the Malvinas.
Castro had called Britain's £180-million ($265-million), 10-year plan to beef up its defenses on the islands "an excuse used by the military to lobby to keep spending money."
Kirchner for her part said last week at commemorations to mark the 33rd anniversary of Argentina's ill-fated invasion of the Falklands: "We will once again see the islands form part of our territory."
A British Foreign Office spokesman said in a statement explaining why Castro was summoned: "The UK has no doubt about its sovereignty over the Falkland Islands and surrounding maritime areas, nor about the Falkland Islanders' right to decide their own future."
Argentina responded by summoning British Ambassador John Freeman to deliver a tongue-lashing of its own.
It said the ambassador was summoned over news portal TN's reports that documents leaked by fugitive US intelligence analyst Edward Snowden showed Britain's Joint Threat Research Intelligence Group carried out a "long-term, far-reaching" espionage program in Argentina.
"Actions of this sort violate the right to privacy," Argentina's Deputy Foreign Minister Eduardo Zuain told the ambassador Thursday, according to a foreign ministry statement.
Argentina claims it inherited the remote, wind-swept islands from Spain when it gained independence.
Britain argues it has historically ruled them and that the islanders should have the right to self-determination. In a 2013 referendum, 99.8 percent voted to remain a British overseas territory.
The 74-day Falklands War claimed the lives of 649 Argentine soldiers, 255 British soldiers and three islanders.