- Witnesses say the 200,000 marchers quickly dispersed after the shooting
- A security official says the troops were defending themselves against armed marchers
- An even larger march is planned for Friday, opposition parties say
Government troops shot at protesters marching in the southwestern city of Taiz , injuring 12, medical workers in the city's Freedom Square said Thursday.
Two of the injured were in critical condition, they said.
The medical workers said nearly a hundred people were suffering from tear gas inhalation.
Eyewitnesses said hundreds of bullets were shot by the troops, and that the march was dispersed within minutes after the shooting began.
At least 200,000 youth participated in the march, many of them women, witnesses said.
Taiz is the capital of the province of the same name, Yemen's largest. It is considered the heart of the Yemeni revolution and has had the largest number of anti-government protesters.
"The regime believes that it is strong. They are not stronger than the will of the people," said Sameera al-Areeqi, a rights activist in Taiz who was among the marchers.
The shooting took place near the Taiz security headquarters building.
Numerous eyewitnesses said pro-government snipers were seen on roof tops.
A security official in Taiz did not deny that troops shot live bullets, but said that they were defending themselves after youth protesters shot at the troops.
"Not all the youth protesters are unarmed. Some of them have guns and shoot at our troops," said a security official in the province who is not authorized to talk to the media and declined to be named. "We cannot watch our troops get shot and do nothing,"
Youth protesters are urging opposition and military leaders to stand with them in putting an end to the regime of President Ali Abdullah Saleh. "We cannot stall our revolution. Months have passed and we are still protesting and marching," said Salmad al-Mikhalfi, one of the young protesters.
"We need to have an immediate solution to oust Saleh from power," he added.
Protests in Yemen have been going on since January 16.
At least 450 youth protesters have been killed by government forces since the beginning of the year, the HOOD human rights organization reported.
"The government will stand responsible for every blood that was spilt, whether today, tomorrow, or the near future," said Abdul Rahman Barman, HOOD's executive director.
Opposition parties are preparing for a march Friday that they say is expected to gather millions of youth.