Protestors in Argentina burned an effigy of Prince William after President Christina Kirchner branded the British rule of the Falklands "absurd" on the anniversary of the war.
Militant protesters gathered outside the British embassy in Buenos Aires to burn the effigy and Union Jack flags on the 30th anniversary of the Falklands War.
Petrol bombs were thrown at police, who responded by firing teargas into the crowds. Several people were injured.
The Duke of Cambridge recently returned from a six-week tour of the Falkland Islands, a move which was criticised for being organised shortly before the anniversary when emotions in the terriotiral dispute were already heightened.
The conflict claimed the lives of 649 Argentines and 255 Britons.
Kirchner commemorated the anniversary by delivering a speech in the southernmost city of Ushuaia which she said it was "absurd" that Britain owns the islands, locally known as the Malvinas.
"We are not here to commemorate war. War only brings poverty, violence, and makes things go backwards. Nothing good comes out of war. We just want a more just and peaceful world for everybody," Kirchner said beside a monument to those who died during the conflict.
"It is absurd to claim control [of the Falklands] from 14,000km (8,700 miles) away when the territory is on our continental shelf," Kirchner said in a 20-minute speech to veterans of the 74-day conflict.
"It is an injustice that in the 21st century, a total of 16 colonial enclaves still exist, including 10 ruled by Britain.
"We demand justice so Britain doesn't continue to pillage our environment and natural resources," Kirchner said.
Tensions over the islands have flared up again over the past two years after Britain gave companies permission to search for offshore oil deposits in territorial waters off the archipelago. Suspected deposits are thought to be worth tens of billions of pounds
The Falklands are about 300 miles off Argentina's coast and are home to about 3,000 inhabitants. The island have been declared of the British Overseas Territories since Britain established colonial rule in 1833.