SANAA— Opponents of Yemen's embattled president marched in cities and towns across the nation after Friday prayers.

In the capital Sanaa and elsewhere, hundreds of thousands chanted against Saleh, while renegade military troops made up defectors provided security to the opposition demonstrations, AP reported.
In the southern city of Taiz — an opposition hotbed — a massive crowd also gathered Friday to demand Saleh step down.
Reinforcements of Republican Guard units and special forces were deployed in positions overlooking the protest in Sanaa, as well as around the Foreign Ministry and sensitive military headquarters.
Opposition activist Walid al-Ammari said Friday's demonstration, with the participation of huge number of women, was ""a message to this ruler (Saleh) to step down immediately without any promises of immunity from trial.""
Saleh and the opposition are considering a Persian Gulf Arab nations' proposal to end the country's crisis.
The draft calls on Saleh to hand over power to a successor of his choice and leave within a month, safe from the possibility of prosecution. The opposition wants him to leave immediately and the talks with the Persian Gulf Cooperation Council representatives have failed to break new ground.
Meanwhile, authorities in Yemen have moved against military figures who defected from the camp of the country's embattled president to join the opposition, arresting several officers on Friday, according to a military official.
According to AP, the arrests followed a demonstration at al-Anad air base in the southern Lahj province on Tuesday, where dozens of soldiers and airmen joined the calls for the president to step down, said the military official, who spoke on condition of anonymity for fear of reprisals.
The official, who holds the rank of a colonel, said several senior officers were detained but would not elaborate.
Human rights groups have said that at least 58 activists and opposition supporters have been detained in the past three weeks, including more than 20 protesters who were injured in clashes with police in Sanaa on Saturday.
------ Yemenis use social networks
Meanwhile, Yemeni protesters upload videos and pictures of their revolt on social networks from Internet cafes around a square outside Sanaa University, which has become the epicenter of demonstrations demanding Saleh's departure.
""We use Facebook to share some of our videos and pictures from the protests. It is like an operation room that we distribute the truth and reality of Yemeni revolution through,"" Ibrahim Shamakh, 24, told AFP.
Networking websites played a significant role in mobilizing demonstrators and distributing footage of the uprisings in Egypt and Tunisia.
They also continue to contribute strongly to the coverage of unrest in Bahrain, Libya and Yemen.
Many in the Arab world have grown to trust material diffused through social media networks on the Internet, to fill a gap in information caused by state censorship.
Around 130 people have been killed since protests broke out late January.
On March 18, regime loyalists gunned down 52 people near the Taghyir square, prompting the president, who has been in office since 1978, to declare a state of emergency.
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Photo: Anti-government protestors shout slogans during a demonstration demanding the resignation of Yemeni President Ali Abdullah Saleh in Sanaa, Yemen, Thursday, April 21, 2011. (AP Photo