Forces loyal to Yemen's embattled president opened fire on protesters demanding his ouster Monday, killing two and wounding dozens at various protests, activists said.
The latest violence came as a Gulf Arab proposal for President Ali Abdullah Saleh to step down appears increasingly doomed, raising prospects of more bloodshed and instability in a nation already beset by deep poverty and conflict.
Yemen's unrest erupted over two months ago, inspired by uprisings in Tunisia and Egypt. The near-daily protests against Saleh, the country's ruler of 32 years, have demanded he relinquish power immediately.
Monday's deaths came during protests in the cities of Ibb and Bayda, said activist Ibrahim al-Budani.
In the city of Ibb, 120 miles (190 kilometers) south of the capital Sanaa, demonstrators set fire to two cars used by government-paid thugs who shot at them but the attackers managed to flee, he said.
In the southern city of Taiz, presidential guard troops, who are run by Saleh's eldest son, fired bullets and tear gas into tens of thousands of protesters gathered there, according to activist Nouh al-Wafi.
Dr. Sadeq al-Shujae of Taiz said more than 41 protesters were wounded when police opened fire and six people had to undergo critical operations.
Al-Wafi said the protesters were rallying for Saleh's ouster with a simple chant: "Leave!" He said the troops prevented ambulances from getting to the wounded, and that several people and local journalists were arrested.
Also Monday, some six demonstrators were hurt by plainclothes police and thugs who threw stones at a huge rally in the capital Sanaa, according to Abdul-Malek al-Youssefi, an activist and protest organizer.
On Saturday, Saleh agreed to a formula by a Gulf Arab group, the Gulf Cooperation Council, for him to transfer power to his vice president within 30 days of a deal being signed in exchange for immunity from prosecution for him and his sons.
A coalition of seven opposition parties generally accepted the deal but thousands on Sunday remained in a permanent protest camp in Sanaa, and their leaders said they suspected the president is just maneuvering to buy time and cling to power, as he has done in the past.
The protesters claim the opposition parties taking part in the talks with the GCC mediators do not represent them and cannot turn off the rage on the streets. They also insist they would not accept anything short of Saleh's immediate departure.
Saleh has managed to survive politically thanks in part to the loyalty of the country's best military units, which are controlled by one of his sons and other close relatives, and despite defections by many close allies in his party, his tribe and some military units.
More than 130 people have been killed by security forces and Saleh supporters since the unrest erupted in early February. At least 40 were killed in a single attack on March 18 by rooftop snipers overlooking protesters in Sanaa.
The GCC countries, including powerful Saudi Arabia, have been trying to broker an end to the crisis, fearing the potential blowback of more instability in the fragile country on the southern tip of the Arabian Peninsula that also hosts an active branch of al-Qaida.
The official SABA news agency reported Monday that a main power plant in Marib, an al-Qaida stronghold southern province, was attacked for the second time this month. The report said two power transmission lines were cut and accused unnamed "saboteurs" of being behind the attack.
SABA also reported that big pro-government demonstrations were held in the cities of Ibb, Hodeida, Damar and in the northwest Hajja province in support of Saleh's call for dialogue with the opposition and in "defense of the constitutional legitimacy."