Yemen's Attorney General Abdullah Al-Olufi on Wednesday urged the caretaker government to order an immediate investigation into the carnage of the antigovernment protesters on March 18.

He said those who were responsible for killing almost 60 protesters and injuring hundreds of others should be identified and brought to justice soon.

If the security authorities don’t indentify those responsible for the massacre including those who were masked I will resign, he threatened, as the public and external pressure mounts on President Saleh to step down.

On March 18, snipers, who were believed to be security personnel out of uniform, sniped the protesters from inside and over buildings nearby the square of change outside Sana'a University.

President Saleh emerged a few hours after the incident, accusing the people who live at the square clashed with the protesters calling for his ouster, denying the security forces had been involved.

But later, the people, who live nearby the square, said they were not responsible for the attacks on the protesters and told media elements from the national security were to blame for the massacer.

Meanwhile, hundreds of thousands of people have been conducting sit-ins in the squares of change and freedom in most of the Yemeni cities including the capital Sana'a to call for an immediate exit of President Saleh.

More recently, the antigovernment protesters have escalated their protest holding massive demonstrations in which millions marched in the streets condemning the deadly crackdown on the protests and demanding Saleh to stand down immediately.