SAN'A, Yemen -- U.S.-backed President Ali Abdullah Saleh, his support crumbling among political allies and the army, warned Tuesday that the country could slide into a "bloody" civil war as the opposition rejected his offer to step down by the end of the year.
Tens of thousands protested in the capital demanding his immediate ouster, emboldened by top military commanders who joined their cause.
Saleh's apparent determination to cling to power raised fears that Yemen could be pushed into even greater instability. Rival factions of the military have deployed tanks in the capital, with units commanded by Saleh's son protecting the president's palace, and units loyal to a top dissident commander protecting the protesters.
The defection on Monday of Maj. Gen. Ali Mohsen al-Ahmar, a powerful regime insider who commands the army's 1st Armored Division, has been seen as a major turning point toward a potentially rapid end for Saleh's nearly 32-year rule.
The question is whether the Yemeni chapter of the Mideast uprisings will read more like Egypt, where the resignation of President Hosni Mubarak set the country on a relatively stable move toward democracy, or like Libya, which has seen brutal fighting between armed camps.
Clashes broke out late Monday between Saleh's Republican Guard and dissident army units. Yesterday, Guard tanks surrounded an air base in Hodeida after its commander, Col. Ahmed al-Sanhani announced he was joining the opposition.
The turmoil raised alarm in Washington, which has heavily backed Saleh to wage a campaign against an major Yemen-based al-Qaida wing that plotted attacks in the United States. Defense Secretary Robert Gates, on a trip to Russia, refused to weigh in on whether Saleh should step down.