President Evo Morales has said that an alleged assassination plot against him by Balkan mercenaries and an Irishman may have been backed by the US embassy in the Bolivian capital La Paz.

Police commandos shot dead three men last week in a hotel room in the eastern city of Santa Cruz, which was said to be the base for a conspiracy to wipe out government leaders and stage a coup.

Irish authorities are attempting to repatriate the body of Michael Dwyer, 24, one of the trio whose bullet-ridden bodies were displayed in photographs published in Bolivian newspapers.

Two survivors of the group, reported to be a Croatian and a Hungarian, were moved to a jail in La Paz over the weekend, while diplomats, politicians and law enforcement officials tried to ascertain the full picture. Opposition leaders accused the government of jumping to conclusions and manipulating the incident to suit its own purposes.

Morales, Bolivia's first indigenous president and an outspoken critic of the US, elaborated on the alleged conspiracy while attending a regional summit in Trinidad and Tobago. He told a news ­conference that he had asked Barack Obama, in a closed session with 12 South American leaders, to repudiate the plot, which Morales said might be linked to previous US-backed efforts to unseat him.

If the US president did not repudiate the alleged conspiracy, "I might think it was organized through the [US] embassy", said Morales. "I don't want meddling in my country." Obama replied that he was unfamiliar with the incident but assured Morales that his administration was not involved, said a US official at the summit.

Interpol offered to help the police investigation in Bolivia. The mystery began last Thursday when police said that an attempt to arrest a gang of mercenaries led to a gun battle in a hotel room, leaving three dead and a pile of intercepted weapons. No police officers were injured, and it was unclear if the suspects, who were killed in their underwear, had opened fire.

Officials said the group probably had been responsible for a recent dynamite attack on the residence of a Catholic ­cardinal, Julio ­Terrazas, and that it had plotted to go on to mount a "spiral of ­violence" by killing Morales, his vice president, and his chief of staff, as well as opposition leaders.

"The terrorist group had a strategy, and part of the strategy was to attack the cardinal and [take] other actions, not only against the president or vice president, but other authorities as well," said the deputy interior minister, Marcos Farfan.

In Ireland, Dwyer's family in Tipperary said they were shocked, and appealed for privacy. Dwyer was a student at the ­Galway-Mayo Institute of Technology, but on the Facebook website he had posted photos of himself in military gear and holding fake weapons. Some Irish commentators describe him as a fantasist.

The other dead were named as Eduardo Rozsa Flores, 49, a Bolivian-Hungarian who reportedly fought in the former Yugoslavia, and ­Magyarosi Arpak, a Romanian who was said to be a sniper.

The two detained were named as Mario Francisco Tadik Astorga, 58, reportedly a Bolivian-Croatian who also fought in the Balkans, and Elot Toazo, a Hungarian and a computer expert.

www.guardian.co.uk/world/2009/apr/20/evo-morales-bolivia-us-embassy