Yemeni riot police charge towards anti-government demonstrators during a demonstration demanding the resignation of President Ali Abdullah Saleh in Sanaa, Yemen, Friday, Feb. 18, 2011. Anti-government demonstrators clashed with supporters of Yemen's longtime ruler and riot police, who fired tear gas and shots in the air to disperse the crowd on what organizers called a "Friday of Rage" across the country. In the city of Taiz, what appeared to be a hand grenade was thrown at a group of protesters, seriously wounding at least eight people in the blast and stampede that followed, witnesses said. (AP Photo/Muhammed Muheisen)
SANAA, Yemen (AP) -- Yemeni security forces firing from rooftops and houses shot at tens of thousands of anti-government demonstrators, killing at least 31 as the protesters entered a downtown square in the capital to demand the ouster of their autocratic president.
Friday's violence is the harshest response yet from President Ali Abdullah Saleh, a key -- if uneasy -- ally in the U.S. campaign against al-Qaida who has ruled Yemen for 30 years.
Thousands also rallied Friday in the cities of Taiz and Adan, their protests inspired by the unrest across the Arab world that toppled rulers in Egypt and Tunisia. But the government response has been far harsher in Yemen.
Demonstrators have camped out in squares across Yemen for over a month to demand that Saleh leave office. Security forces and pro-government thugs have used live fire, rubber bullets, tear gas, sticks, knives and rocks to suppress them. The protesters say they won't go until Saleh does.
Before the shooting Friday in Sanaa, a military helicopter flew low over the square as protesters arrived from prayers. Thick gunfire soon erupted from rooftops and houses near one of the square's main entries, sending protesters scrambling for cover.
Doctors at the makeshift field hospital near the protest camp at Sanaa University confirmed at least 31 dead, three of them children. They spoke on condition of anonymity because they were not authorized to speak to the media.
The protests are just one of the problems in this extremely poor, tribal country. Saleh's weak central government also faces one of the world's most active al-Qaida branches, a secessionist rebellion in the south and a Shiite uprising in the north.