At least 19 people were killed and hundreds of others were injured when Yemeni security forces opened fire to disperse the protesters in Yemen's capital city and provinces on Wednesday, said witnesses and doctors.

In capital Sanaa, security forces stormed a camping square of tens of thousands of anti-government protesters on Wednesday evening, leaving at least 14 protesters killed, 236 others wounded by gunshots, another 241 injured by batons and stones as well as 735 suffered from suffocation due to tear gas, a doctor at the field hospital told Xinhua.

Earlier in the day, a protester was killed in Sanaa when he marched to the presidential palace along with other demonstrators.

Security forces, using heavy machine guns and tear gas, were still firing and besieging the protesters' square from all entrances outside Sanaa University, in an apparent attempt to break into the square, said a Xinhua correspondent at the scene.

Witnesses said that large security backup have reached to the southern entrance of the protesters' square as the tension intensified.

Clashes between security forces and tens of thousands of anti- government protesters demanding the immediate ouster of President Ali Abdullah Saleh in Yemen's western Red Sea province of Al- Hodayda on Wednesday evening, killing at least one protester and injuring dozens others, doctors and witnesses said.

Meanwhile, protesters in provinces of Taiz and Ibb managed earlier in the day to paralyze their cities after they took control of several government buildings.

In the southern province of Taiz, 200 km south of Sanaa, police on Wednesday morning killed at least three protesters and injured dozens others after the latter set a police station on fire and seized several government buildings, according to witnesses.

Also on Wednesday, a march by tens of thousands of protesters in the southern province of Ibb, 150 km south of Sanaa, took control of the provincial building after they clashed with police forces, witnesses said, adding that tens of protesters and policemen were injured.

The opposition Joint Meeting Parties (JMP) issued a statement late Wednesday to condemn the deadly crackdown on the peaceful protesters, calling on the international community, including the Gulf Cooperation Council (GCC) countries, to help stop Saleh's forces from killing the armless protesters.

A recently GCC-mediated conciliation initiative for power transition between Saleh's ruling party and the opposition stalled after Saleh refused to sign it as Yemeni president, but rather the chief of the ruling party, which violated the GCC initiative's terms.

Yemen's major cities have faced almost daily clashes between police forces and anti-government protesters since mid February.