SANAA (Reuters/AFP) - Opponents of Yemen's president stepped up a campaign on Friday to force him out, but Ali Abdullah Saleh was defiant as he addressed thousands of supporters and urged the opposition to join peace talks. "We call on the opposition to consult their consciences and come to dialogue and reach an agreement for the security and stability of the country," Saleh told supporters at a rally. Worried that al Qaeda's active Yemen wing will exploit a prolonged standoff in the impoverished country, Yemen's Gulf Arab neighbours have offered to mediate an end to the crisis. Saleh's opponents have rejected that offer, however, fearing that talks in Riyadh, long an ally of Saleh, would seek to keep him in office until his term ends in 2013. A shrewd political operator and long-serving ally of the United States, Saleh has warned of civil war and the break-up of Yemen if he is forced to step aside before organising parliamentary and presidential elections. He has offered the new elections this year as part of political reforms, but says he should stay in power to oversee the change or hand over to what he calls "safe hands". Even before the protests inspired by uprisings that toppled the leaders of Egypt and Tunisia, Saleh was struggling to quell a separatist rebellion in the south and cement a truce with Shia rebels in the north. Saleh's speech on Friday came as hundreds of thousands protested against him in Sanaa, Aden and Taiz, and clerics and tribal leaders who were once his allies issued a statement saying the president must go now and his relatives in the military and the security forces must be dismissed. "It's only a matter of days before this regime is over. This revolution cannot be defeated. Our aim is to bring down corrupt family rule," preacher Abubakr Obaid told worshippers near Sanaa University, where protesters have camped out since February. Diplomatic sources say talks had stalled in recent weeks over Saleh's desire for immunity from prosecution for himself and his family. The Gulf plan announced on Sunday appeared to promise Saleh immunity, and he accepted it the next day. The opposition coalition, which includes the Islah party, said on Thursday it refused to go to Riyadh talks because it wanted to focus on forcing Saleh out within two weeks. Opposition leader Mohammed al-Mutawakkil said dissidents could reach a deal that protects Saleh from prosecution, leaving the timing of a power transfer as the main holdup. At least 116 people have died in two months of protests which security forces have attacked with live fire and tear gas. Though Friday saw widespread rallies against Saleh around the country, there was less violence than in previous weeks. Seven protesters were hurt in Taiz when Saleh loyalists opened fire on some tens of thousands who took to the streets after prayers, witnesses said. US-based Human Rights Watch accused the government of using soldiers who appeared to be younger than 18. "The Yemeni government has for too long placed children at grave risk by deploying child soldiers on the field of battle," said Joe Stork, HRW deputy Middle East director. "President Saleh's opponents should not perpetuate the problem by using children for security on the field of protest." Activists distributed leaflets calling on people to stop paying taxes, electricity and other bills to the government in an effort to squeeze Saleh's cash-strapped government further. Strikes in schools and government offices began in the southern city of Aden last week. Meanwhile, a convicted killer of a Yemeni Jew and nine other people on death row escaped on Friday from Amran prison, near the Yemeni capital, after killing three guards, a security source told AFP. "The 10 prisoners escaped after shooting dead three guards and wounding another three" at Amran prison, 50 kilometres (35 miles) north of Sanaa, he said, declining to be named or to give further details on the breakout. He said Abdel Aziz Yahia al-Abdi, who was condemned to death in 2010 for the murder of a member of Yemen's small Jewish community, was among the escapees. Masha Yaishe Nahari, a father of nine, was shot dead in December 2008. The jailbreak comes at the start of a third month of anti-regime protests across Yemen aimed at ousting President Ali Abdullah Saleh.