Sanaa, Yemen (CNN) -- Two protesters were killed Monday in Yemen as government forces battled demonstrators, according to witnesses and medical personnel.
The violence came as people took to the streets in several cities across the country to launch the latest round of demonstrations. The crowds numbered from several hundred to several hundred thousand in some places, witnesses said.
Dozens were reported wounded when security forces tried to disperse the rallies, witnesses said.
In Baitha Province, a protester was killed when armed men in plainclothes fired at the crowd, witnesses, medical staff, and journalists at the scene said. Witnesses said the armed men were security forces.
The incident took place when an estimated 20,000 people came out to protest. The protesters were chanting slogans against President Ali Abdullah Saleh when the shootings took place, the witnesses said.
In Ibb Province, another protester was killled and at least 55 were injured, witnesses and medical staff said. Seven were injured by gunfire, while dozens of others were beaten by batons or hit by stones, the witnesses and medical officials said.
After gunmen opened fire in Ibb, protesters set one of their cars on fire, witnesses and journalists at the scene said.
In Taz Province, security forces took into custody more than 50 demonstrators, witnesses said.
CNN was not able to idependently verify the witness accounts.
Over the weekend, the protests spread across 14 provinces, despite Yemeni officials saying that Saleh had accepted a deal brokered by the Gulf Cooperation Council (GCC) under which he would step down.
Both Saleh and the Yemeni opposition have agreed to the deal in principle. But Saleh has yet to sign the agreement, which stipulates he leave office within 30 days and provides complete immunity for him and those who served in his regime, said a senior Foreign Ministry official, who requested anonymity because he is not authorized to speak to the media.
The agreement also calls for a unity government to be formed within seven days.
Yaseen Noman, president of Yemen's largest opposition group, the Joint Meeting Parties (JMP) bloc, told journalists Saturday that members accepted the GCC proposal but had two comments -- they did not want to participate in a unified government, and they cannot force protesters to go home.
The Organizing Committee of the Youth Revolution denounced the proposal in a written statement Sunday.
"We the youth of revolution reject any proposal that does not hold Saleh accountable for the killing over 140 revolution protesters," the committee said.
The group also said it rejected the GCC proposal because it did not call for an immediate ouster of Saleh. The committee also said the GCC effort came to save the regime -- not to help the people.
Mohammed Albasha, spokesman for the Yemeni Embassy in Washington, said the opposition has to accept the final deal before Saleh will sign.
According to Yemeni government spokesman Abdu Ganadi, the ruling party said the opposition must accept the proposal completely or reject it -- partial agreements will not be accepted.
The GCC -- a bloc of six oil-producing Gulf nations -- has been working to ease tensions between Saleh and an increasingly restive opposition.
Violent anti-government demonstrations have erupted for many weeks across Yemen.
Saleh has been in power since 1978 and served as a staunch U.S. ally in the fight against al Qaeda in the Arabian Peninsula.
CNN's Christine Theodorou and journalist Hakim Almasmari contributed to this report.