Update at 12:14 p.m. ET: Yemen's embattled president warns of civil war from what he charges are attempts by the opposition to mount a coup to oust him.

"Those who want to climb up to power through coups should know that this is out of the question. The homeland will not be stable, there will be a civil war, a bloody war," he says, according to the BBC.

Earlier posting: Yemeni opposition forces have rejected an offer by President Ali Abdullah Saleh to step down in January 2012, Al-Jazeera TV reports.

Saleh on Monday night offered to resign in January 2012 after organizing parliamentary elections.

A coalition of Yemeni opposition groups rejected the offer, Al-Jazeera reports, saying "the coming hours will be decisive."

Al-Jazeera notes that Saleh, who has been in power for 32 years, has broken similar promises in the past, including a pledge in 2005 not to run for another term.

Monday, three top Yemeni generals and several senior diplomats either defected or resigned, joining the call for Saleh to step down.

Demands for his resignation have intensified since security forces fired on demonstrators March 18, killing almost 50 people.