Anti-government protesters attend a protest in Saana, Yemen, May 6, 2011. Yemeni President Ali Abdullah Saleh on Friday told a rally of his supporters that he would remain "steadfast" in resisting his opponents' demand of his immediate ouster. [Yin Ke/Xinhua]

Iran's Foreign Ministry said the wave of unrest in Syria was a plot by the United States to drive a wedge between the Syrian people and their government.

The ministry warned Syrians against U.S. and Israeli plots to undermine the country's national solidarity and sovereignty and denounced Washington's double-standard stance on Syria.

Meanwhile, in Yemen, President Ali Abdullah Saleh told a rally of supporters he would remain "steadfast" in resisting opponents' demand for his immediate ouster.

"I will remain steadfast like mountains," Saleh told the crowds who gathered near the presidential palace in the capital Sanaa. He added that there was no place for the opposition's "projects of revenge, anarchy and sabotage."

Government supporters called on Saleh to stay in office until his presidential term ends in 2013 in accordance with the Constitution.

A few miles away, tens of thousands of anti-government protesters gathered near Sanaa University, repeatedly calling for an immediate end to Saleh's 33-year rule.

Major cities in almost 15 provinces witnessed both anti- and pro-government protests.

As long lines of trucks and buses waited at some gas stations in Sanaa to fuel up, dozens of other stations closed after their supplies ran out.

Many Yemenis were also facing daily hours-long blackouts and weeks of water and cooking gas shortages.

The Gulf Cooperation Council (GCC) prepared to hold the signing ceremony of the GCC deal in Sanaa to solve the political crisis in the country, the Yemeni Defense Ministry said Thursday.

The ministry said it had learned from Yemeni officials that Saleh was expected to sign the deal after representatives of his ruling party and the opposition inked it in Sanaa.

Yemen has witnessed an endless stream of pro- and anti-government protests since mid-February. Some of the protests developed into fierce clashes, killing or injuring many members from both camps.