Moscow, April 25 (IANS) Hundreds of thousands of protesters took to the streets across Yemen Sunday against President Ali Abdullah Saleh, with the biggest demonstrations staged in the capital Sana'a.

Protesters in the impoverished Arabian Peninsula state demanded immediate departure of President Ali Abdullah Saleh despite a transition plan drawn up by the Gulf Cooperation Council (GCC), a bloc of six oil-producing Gulf nations, under which he would leave office within 30 days, and presidential elections would follow a month later, RIA Novosti reported.

Saleh is yet to sign the agreement, which also provides complete immunity for him and his family.

Yemeni opposition parties have welcomed the deal but refused to join a unity government with the ruling General People's Congress party.

On Sunday, in an interview with the BBC, Saleh described the protest movement as a "coup," and said the transfer of power should be implemented "through ballot boxes and referendums".

At least 120 people have been killed in two months of protests against Saleh's 32-year rule.