TORONTO, CANADA (AFP) - The United States denounced Sunday (April 22) police violence in Nicaragua where more than 20 people have died in a wave of protests, urging the government to allow journalists to work freely.

Violence erupted in the capital Managua on Wednesday (April 18) after police attacked demonstrators protesting over plans to reform the pension system, with the unrest spreading to other cities.

In a statement, the US State Department expressed regret over the loss of life and urged Managua to prosecute those responsible.

"We condemn the violence and the excessive force used by police and others against civilians who are exercising their constitutional right to freedom of expression and assembly," it said.

A local rights group put the toll at more than 20 dead, with media reports saying one of the victims was a local journalist.

Even before his death on Saturday (April 210, journalists had reportedly come under attack, been temporarily detained and had their equipment stolen, and the government on Thursday took four independent television outlets off air, although only one remains barred.

"We also call on the Nicaraguan government to allow journalists to operate freely and restore all television coverage to the air," the State Department said, urging the government to open an "independent investigation" and to prosecute those behind the killings.

It also called for a "broad-based dialogue involving all sectors of society to resolve the current conflict."

Information on the deaths is still piecemeal, but most of the dead are believed to have been civilians protesting against the reform, although one of the first victims was a 33-year-old policeman who was shot dead, officials said.