The opposition said last week they agreed to resume a long- halted dialogue with Saleh's ruling party, showing readiness to join a unity national government under the supervision of Saleh.

Hours after president's speech, an official close to the consultative board of the opposition coalition told Xinhua on condition of anonymity that the leadership of the opposition has decided to join the protesters in the streets.

Deadly clashes between police-backed government supporters and anti-regime protesters have left more than 10 people dead and hundreds of people injured since the waves of protests spread across the country.

Earlier Monday, security forces arrested four anti-government protesters and prevented others from staging a peaceful rally in southeast province of Shabwa, according to a local official.

In northwestern province of Al-Hodayda, scores of government backers wielding knives and batons clashed Monday with hundreds of anti-regime protesters, leaving dozens injured, according to a police source there.

In the capital of Sanaa, nearly 7,000 anti-regime protesters, mostly students, continued Monday a sit-in outside Sanaa University for asking the long-service president to resign, a police officer in charge of guarding the university said.

The protester erected tents late Sunday at a place they name it "Changing square" in front of the main gate of Sanaa University as security authorities blocked all roads leading to the campus.

Southern provinces of Aden, Taiz and Ibb also witnessed Monday massive rallies demanding the overthrowing of Saleh's power.

In the northern province of Saada, resurgent Houthi-led Shiite rebels staged Monday the first anti-government protest, a group spokesman said.

The Shiite rebel commander Abdulmalik al-Houthi pledged last week to prepare his fighters to support protesters in Sanaa against President Saleh if "the evolution breaks out."

Inspired by the Egyptian popular uprising, thousands of Yemenis took to streets in major cities, including the capital of Sanaa, for 11th consecutive days demanding the ouster of long-serving President Ali Abdullah Saleh.