Yemeni security troops opened fire on Thursday on thousands of protesters calling for a boycott of April parliamentary elections and wounded about two dozen demonstrators, the organizers of the rally said.

An Interior Ministry official said the troops fired into the air to disperse the "illegal" demonstration in the capital San'a, but he refused to comment on any injuries. The official spoke on condition of anonymity because he was not authorized to talk to the media.

The Yemeni Socialist Party said it had called the protest with several other opposition groups because they believe the balloting next April will not be fair, mostly because a 9-member electoral body overseeing the vote is all-appointed by the country's president and its members are closely linked to the ruling party.

Socialist leader Yaseen Said No'man said the opposition has been holding demonstrations across Yemen to protest the government's rejection of amendments to the country's electoral law proposed by the opposition and meant to curb vote-rigging.

No'man said the opposition wants the electoral body to include independent figures and opposition members.

A Socialist Party statement issued after the protest Thursday said 23 people were wounded, three of them critically. It said the police arrested at least 34 protesters.

"What happened in San'a today was a strong expression of the popular rejection of authorities' attempts to falsify the elections," No'man said. "It's clear evidence that people rejects anyone forging their will."

Later Thursday, the interior ministry accused the opposition of attempting to destabilize the country and warned in a statement that the parties would be held responsible for "the consequences of their illegal acts."

Separately, the Yemeni journalists union issued a statement saying the troops using batons and weapon butts beat seven journalists who were covering the rally.

Mohammed Saleh Ahmad, a witness at the rally, said the government troops opened fire and threw bricks and tear gas at the protests, prompting a stampede, which caused some of the injuries.

Yemen is an impoverished country in the south of the Arabian Peninsula, with strong tribal rules and lawless areas. It's also the ancestral homeland of Osama bin Laden.

President Ali Abdullah Saleh has been in power since 1978, ruling North Yemen and then continuing in power after North and South Yemen united in 1990. In the 1999 elections, Saleh won overwhelmingly amid opposition boycotts, claims of vote-rigging and clashes at polling booths that left several dead.

The Socialists are Yemen's second biggest party and ruled southern Yemen before the unification. The country's opposition bloc has 60 members in the 301-seat parliament.