Sanaa, Yemen:
Three Yemeni army commanders, including a top general, defected Monday to the opposition calling for an end to President Ali Abdullah Saleh's rule, as army tanks and armoured vehicles deployed in support of thousands protesting in the capital.
With the defection, it appeared Saleh's support was eroding from every power base in the nation -- his own tribe called on him to step down, he fired his entire Cabinet ahead of what one government official said was a planned mass resignation, and his ambassador to the U.N. and human rights minister quit.
All three officers who defected Monday belong to Saleh's Hashid tribe. A Hashid leader said the tribe, eager to keep the president's job for one of its own, was rallying behind one of the men, Maj. Gen. Ali Mohsen al-Ahmar, as a possible replacement for Saleh.
The leader spoke on condition of anonymity because of the sensitivity of the subject.
Al-Ahmar, the most senior of the three officers, is a long-time confidant of Saleh and commander of the army's powerful 1st Armoured Division. Units of the division deployed Monday in a major square in Sanaa where protesters have been camping out to call for Saleh to step down.
Saleh's crackdown on a month-long uprising against his rule has grown increasingly violent in recent days -- suggesting he is becoming more fearful that the unprecedented street protests could unravel his three-decade grip on power in this volatile and impoverished nation.
He also tried unsuccessfully to calm the protest by pulling back riot police.
The two other officers are Mohammed Ali Mohsen and Hameed al-Qusaibi, who both have the rank of brigadier. Yemen's ambassadors to Jordan, Syria and parliament's deputy speaker also announced Monday they were supporting the opposition, further undermining Saleh's weakening authority.
Tanks and armoured personnel carriers belonging to the Republican Guards, an elite force led by Saleh's son and one-time heir apparent, Ahmed, were deployed outside the presidential palace on Sanaa's southern outskirts, according to witnesses. The deployment appeared designed to counter the presence on the streets elsewhere in the city of elements of the 1st Armoured Division.
News of the defections came one day after crowds flooded cities and towns across Yemen to mourn dozens of protesters killed Friday when Saleh's security forces opened fire from rooftops on a demonstration in Sanaa.
Saleh and his weak government have faced down many serious challenges, often forging fragile alliances with restive tribes to extend power beyond the capital, Sanaa. Most recently, he has battled a seven-year armed rebellion in the north, a secessionist movement in the south, and an al-Qaida offshoot that is of great concern to the U.S.
Al-Qaida in the Arabian Peninsula, which formed in January 2009, has moved beyond regional aims and attacked the West, including sending a suicide bomber who came tried to down a U.S.-bound airliner with a bomb sewn into his underwear. The device failed to detonate properly.
Yemen is also home to U.S.-born radical cleric Anwar al-Awlaki, who is believed to have offered inspiration to those attacking the U.S., including Army Maj. Nidal Hasan, who is accused of killing 13 people and wounding dozens in a 2009 shootout at Fort Hood, Texas.
Al-Ahmar has been close to Saleh for most of the 32 years the Yemeni president has been in power. He is a veteran of the 1994 civil war that saw Saleh's army suppress an attempt by southern Yemen to secede. Al-Ahmar also fought in recent years against Shiite rebels in the north of the country.
Al-Ahmar announced his defection in a message delivered by a close aide to the protest leaders at the Sanaa square that has for weeks been the epicentre of their movement.