Some 300 members of the Teamsters' Union blocked the entrance of the printers of dailies Clarín and La Nación in the City neighbourhood of Barracas in a move to press the companies to enroll staffers in the union.

The protest led to delays of more than two hours in the distribution of the dailies. The newspapers condemned the measure, which both described as an attempt of the government to gag free press.

After the end of the two-hour protests, unionists said they would stage similar demonstrations next week.

The protest in Barracas took place only hours after officials of the Kirchner administration had said the government "would prevent any pickets by the teamsters union." The trade union, led by the son of the CGT Labour Confederation Hugo Moyano, Pablo Moyano,is very close to the Kirchners.

In the previous two nights, teamsters had blocked the access to other printers.