TBILISI, Georgia (AP) — Street protests against the brutal abuse of prisoners escalated Thursday in the Georgian capital, fueling anger against the Western-allied government and possibly boosting support for the opposition before a tight parliamentary election.

President Mikhail Saakashvili has sought to defuse the tensions by removing the Cabinet ministers most blamed for the abuse and completely reshuffling prison personnel.

Two days after television stations aired videos of guards beating inmates and raping them with truncheons and brooms, thousands rallied outside the Interior Ministry and the Tbilisi prison where the abuse occurred. The protesters, some carrying brooms, then marched down the capital's main avenue to the presidential palace to demand the ouster of the interior minister.

Veriko Kapanadze said her son looked scared and tense when she last visited him in prison.

"Now I understand why. It's like a Gestapo prison," she said.

"I'm awfully worried for my son," said another protester, Nargiza Georgadze.

The interior minister, Bachana Akhalaya, resigned late Thursday. Akhalaya said that although he was no longer responsible for Georgia's prisons, some of the prison officials who should have prevented the abuse had worked under him when he headed a Justice Ministry department overseeing the penal system from 2005 to 2008.

Earlier in the day, Saakashvili put Georgia's ombudsman in charge of penitentiaries, voicing hope that he would "fully reform the system." The new interior minister, Yekaterina Zguladze, who had been Akhalaya's deputy, also promised to stamp out abuse in the prisons.

The simmering public anger threatens to damage Saakashvili's party in the Oct. 1 parliamentary election and may boost support for the opposition Georgian Dream coalition led by billionaire philanthropist Bidzina Ivanishvili.

Even some youths linked to the governing party joined Thursday's street protests as Saakashvili and his loyalists sought to distance themselves from the incident.

Saakashvili, who has led Georgia since 2004, has remained popular thanks to economic reforms, anti-corruption efforts and moves to integrate closer into the West. But his image was dented by his handling of a disastrous war with Russia in 2008. The opposition has also accused Saakashvili of a systematic clampdown on dissent and independent media.

Ivanishvili, Georgia's richest man who sold his extensive business assets in Russia to enter Georgian politics, said the videos had confirmed his longtime suspicions about Georgian authorities' brutality.

Irakli Alasania, the leader of a party that is part of Ivanishvili's coalition, said the prison videos have shattered the governing party's image. "It has unmasked Saakashvili's regime, exposing a sadistic mechanism hidden behind its glossy facade," he said.

Saakashvili and his allies have described Ivanishvili as a Moscow pawn who aims to take the tiny nation on the Black Sea back into the Russian fold. Ivanishvili has rejected their allegations, pledging to continue a course toward integration into the West while moving to normalize ties with Russia, which have remained frozen after the war.

Stakes in the parliamentary vote are high. Saakashvili, who is serving his second and final term, which expires next year, has pushed through laws that make the prime minister more powerful than the president. If Ivanishvili's coalition wins, he would become prime minister.

Georgian prosecutors have arrested 12 prison officials and Saakashvili has vowed that all those responsible will be severely punished. At the same time, the Georgian Interior Ministry has accused Saakashvili's political foes of staging the videos, claiming prison officials were paid to orchestrate and film the abuse by an inmate with connections to Ivanishvili. Ivanishvili has rejected the claim.

The prison abuse videos were broadcast by the Maestro and Channel 9 television stations; the latter belongs to Ivanishvili. They said they got the videos from a prison official who has fled abroad.

Some analysts said the incident will play into Ivanishvili's hands in the polls.

"The prison torture videos have dealt a serious blow to the ruling party's authority," said Irakly Menagarishvili, a former Georgian foreign minister who now heads the Center for Strategic Research, an independent think tank.

He said Saakashvili needs to act quickly to save his United National Movement party from being beaten and added that the government has failed to contain the fallout.

Alexander Rondeli, an independent political expert in Tbilisi, agreed that the scandal would take a toll on Saakashvili's party.

Saakashvili may have quelled some of the anger by replacing the interior minister and giving the penitentiaries minister's job to Giorgy Tugushi, the ombudsman who long has criticized Georgia's prisons.

"Now I have a chance to completely reorganize the system and ensure the protection of inmates' rights," Tugushi said.

Gigi Tsereteli, a deputy speaker of parliament from Saakashvili's party, sought to play down the prison videos' impact. He said the "intolerable and outrageous" prison videos have taught a "hard lesson to the government," but insisted that they wouldn't lead to the ruling party's defeat at the polls.

"The government has reacted quickly: a minister has stepped down, and the perpetrators of these crimes have been arrested," he told The Associated Press. "I don't think it will affect our electorate. People have long made their choice in our favor."

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