A Yemeni protester chants slogans calling for the ouster of Prez Ali Abdullah Saleh during a massive anti-regime rally

Vast numbers of protesters poured into a square in Yemen's capital Sanaa on Tuesday for a massive anti-regime rally, as President Ali Abdullah Saleh blamed the US and Israel for a wave of Arab revolts.

Anti-Saleh protesters crowded three streets leading to a square near Sanaa University, where students and pro-democracy demonstrators have been camped for more than a week.

"The people want the departure of Ali Abdullah Saleh," they chanted in unison at the square, which they have dubbed Al-Huriya (Liberty) Square. "The people want to overthrow the regime."

By early afternoon the crowd had swelled to tens of thousands of protesters, all demanding — in speeches and in chants — the ouster of Saleh, an AFP correspondent said.

While the protests raged, Saleh delivered a speech at the nearby university campus during which he accused Israel and the United States of fomenting anti-regime uprisings rattling the Arab world.

"The events from Tunisia to Oman are a storm orchestrated from Tel Aviv and and under Washington's supervision," said Saleh, whose partisans staged their own counter-demonstration on Tuesday at Al-Tahrir square in Central Sanaa.

"Every day we hear a statement by (US President Barack) Obama. (saying) Egypt don't do this, Tunisia don't do that. What does Obama have to do with Oman, what does he have to do with Egypt? You are the US President," Saleh said.

The protesters are "led from outside" and are in the pay of "Zionists," said Saleh, who is facing a crescendo of calls to step down after 32 years in power.

The Yemeni President accused demonstrators in his poverty-stricken Arabian Peninsula country as being nothing more than "copycats."

"What is taking place on Yemen's streets is just a copycat attempt, as Yemen is not Tunisia or Egypt and the Yemeni people are different," he said.

Saleh was referring to revolts that have hit the Arab world, leading to the ouster of Tunisia's veteran Zine El Abdine Ben Ali and Egypt's Hosni Mubarak.

Anger at authoritarian Arab regimes in the West Asia and North Africa is now raging from Algeria to Yemen and has spread to the previously unaffected Gulf states of Kuwait and Oman, both strategic Western allies.

The opposition "wants to drag us into using force and into civil war but we will not get involved in this," Saleh said.

The president had on Monday warned that Yemen would fracture if his regime falls and said his opponents wouldn't be capable of ruling Yemen "for one week."

He has also vowed to defend his three-decade regime "with every drop of blood," accusing his opponents of hijacking protests in a ploy to split the nation.

The UN human rights chief on Tuesday warned Yemeni authorities against violent repression of peaceful protests, saying that people have the right to express their grievances.

"People have the legitimate right to express their grievances and demands to their government," Navi Pillay, UN high commissioner for human rights, said in a statement issued in Geneva.

"We have seen over and over again in the past few weeks that violent responses, in breach of international law, do not make the protesters go away and only serve to exacerbate their frustration and anger," she added.

At least 19 people have been killed during protests and clashes across Yemen since February 16, according to an AFP tally based on reports by medics and witnesses

Rights group amnesty international has put the toll at 27.