At least twelve anti government protesters were killed and over a hundred  injured when the security forces intercepted and attacked a massive demonstration calling for an immediate ouster of the regime in the Yemeni capital Sana'a on Wednesday.

"We don't have enough medicine to treat the over one hundred shot by the government. We call on the international community to give us medicine to save those the government shot from dying," said Dr. Naneeb Ghanem, a senior medical staff member at Sanaa change square.

He added, "the language of bullets and killing is what this regime wants to spread. It's a massacre against humanity and human rights. Eleven have been killed and the number is expected to rise."

The death toll was expected to rise from the attack on the hundreds of thousands of the protesters at the TV and Radio Corporation area, medical sources said.

The security forces are continuing heavy fire after they had failed to stop the demonstrators, who are chanting slogans demanding the resignation of President Saleh and condemning the deadly crackdown on the people seeking change, said Iyad Muhammad, a protester.

The demonstrators also condemned any initiative giving immunity to Saleh and his regime officials, urging Yemen's neighbors and friends to stand by the Yemeni people and cooperate to open trials for the officials responsible for crimes including the killing of the antigovernment protesters, said Iyad.

"The forces are firing live bullets at us but they never used teargas," he added.

The demonstration comes amid the escalation of the protests seeking the ouster of the regime in most of the Yemeni cities and after the political rivals delayed the signing of an agreement for implementing the GCC plan to tackle the Yemeni crisis.