A swastika painted on a US flag flashes across the screen. Out of sight a voice proclaims: "Let's recover our memory and history from the claws of the Empire ..." The voice is replaced by anti-imperialist chants and metallic sounds, then the screen goes dark.

Welcome to Telesur, Latin America's answer to CNN and the BBC World Service.

A few minutes after 12pm local time on Sunday the new TV channel began broadcasting a pilot service from studios in the Venezuelan capital, Caracas, with a team of 25 journalists in nine regional bureaux presenting news "from a Latin American perspective".

Telesur promoters describe it as an antidote to western-controlled media hegemony. But even before its launch the channel was being attacked in Washington as a vehicle for anti-US propaganda, with the House of Representatives last week voting to enable the US to broadcast its own signals into Venezuela in retaliation.

In response, Hugo Chavez, Venezuela's left-leaning president, threatened to engage in "electronic warfare" with the US if the amendment makes it through the Senate.

The war of words has made for a painful birth for the new channel whose 36-strong advisory committee - designed to offer it an aura of legitimacy - include Nobel-Laureate Adolfo Pérez Esquivel, film directors Pino Solanas and Jorge Sangines, and writers Richard Stallman, Eduardo Galeano and Tariq Ali.

Telesur's director, Aram Aharonian, says the committee's goal is to remind Telesur of its objectives: to help integrate the continent, show perspectives on Latin American countries ignored by large corporations such as CNN and Reuters, and incorporate those without a voice to transform the region's unfair structures.

The channel will also show classic and contemporary Latin American films and a mix of experimental documentaries by young filmmakers.

"We've bought part of the offer available, but we're discovering everyday new young directors," says Telesur's producer Nohra Rodriguez, amid the excited buzz of the 60, mostly young, staff coming from across Latin America.

If the pilot succeeds, Telesur's staff will rise by September to 150 with inhouse programming jumping from four to eight hours a day, adding new features such as in-depth news reports, and regional music and tourism shows.

All will be produced for and by Latin Americans, except some contemporary independent films dubbed Nojolivud (No Hollywood).

Although Telesur is backed by the governments of Argentina, Cuba, Uruguay and Brazil, the driving force has been President Chavez, whose government has contributed 70% of Telesur's $10m (£5.7m) financing and owns 51% of the channel. Real power inside Telesur will rest on a seven-strong board of directors led by Venezuela's communications minister, Andres Izarra - "the Turner of Telesur" as he is dubbed, in reference to Ted Turner, founder of CNN.

The direct involvement of Caracas has fuelled criticism in the US. Ties between the two countries have deteriorated in the last few years, most notably after the implicit support by the US for the failed coup against Mr Chavez in April 2002, and Washington's rising anger over the Venezuelan president's close association with Cuban leader Fidel Castro.

At the heart of US concern is Venezuela's position as one of the US's most important - and until recently reliable - oil suppliers. Last week's amendment to the Foreign Relations Authorisation Act allowing the beaming of pro-US television and radio broadcasts into Venezuela was supported by both Republicans and Democrats, with one member of Congress accusing Mr Chavez of being a "menace in our hemisphere".

But the new channel Telesur has not been immune to criticism in Latin America, with some dubbing it "Telechavez".

Critics say that in December Mr Izarra was responsible for passing a new media law allowing the prosecution of opposition TV and radio stations and that Telesur's headquarters are located in an annex belonging to Venezuela's communications ministry.

During Sunday's launch Mr Izarra told Telesur's audience that the station was not directed against the people of the US, but was "erupting onto the international scene" to counter cultural imperialism.

The channel's first news programme began with a critical report on the failure of the humanitarian mission in Haiti, led by Brazil, followed by a story on the plight of refugees in Colombia.

If Telesur continues in a similar vein the US may not be the only country to have its feathers ruffled by the new television station.