Populist leaders around Latin America are increasingly making legal and political moves to silence their media critics, the president of the Inter American Press Association said Friday.

Tactics include revoking broadcast licenses, fostering hostility toward journalists and giving a free hand to government supporters who have attacked broadcast stations, newsrooms and printing plants.

"We are extremely concerned at the growing level in recent weeks of harassment and violence in various countries," Enrique Santos Calderon told The Associated Press at the opening of the regional association's annual meeting in Buenos Aires. "Democratic systems require a free and unfettered press."

In Argentina, top editors are criticizing President Cristina Kirchner, who signed a decree this week ordering newspapers and magazines to be sold exclusively in union-run stands. Editors fear the government will now be able to prevent the distribution of newspapers that don't follow the ruling party line by enlisting pro-government unions to shut them down.

"From now on the sale of newspapers will be the only commercial activity regulated by the state," said Gregorio Badeni, a constitutional law expert in Buenos Aires. "It is obvious that they aim to curtail the free development of the newspaper business, because they're putting conditions on the sale of their products."

Fernandez didn't respond to an invitation to speak at the IAPA meeting, where attacks on press freedoms dominate the agenda.

But Fernandez openly sided with Argentina's powerful labor movement this week. Truckers union boss Hugo Moyano sent his members to block the distribution of Clarin, La Nacion, Perfil and other print media, demanding that drivers be put under the union.

Interior Minister Florencio Randazzo denied any government role in the bare-knuckled union moves by Moyano, who runs Argentina's largest union confederation and also is a close ally of Fernandez's husband, former President Nestor Kirchner.

"There are those who want to make it look like there's a dark government hand trying to stop the democratic and popular media ... nothing could be further from the truth," Randazzo told the Argentina News Agency.

The IAPA also has criticized Argentina's new broadcast media law, a ruling party project that preserves two-thirds of the radio and TV spectrum for noncommercial stations and gives political appointees a powerful role in granting licenses and regulating content.

Unless legal challenges succeed, Grupo Clarin _ a frequent Fernandez critic and one of Latin America's largest newspaper and cable TV companies _ will be forced to sell many of its properties within a year.