Monday’s killings take to nearly 30 the number of protesters killed by government forces since Sunday night. It was the bloodiest assault in months on demonstrators calling for the president’s ouster.

The officials say the three were shot dead by snipers on Sanaa’s central Hayel street. They say three other protesters were wounded Monday by sniper fire near Sanaa University. The officials spoke on condition of anonymity because they were not authorized to share the information.

Tens of thousands of protesters demonstrated in Sanaa Sunday to press demands for President Ali Abdullah Saleh to step down after 33 years in power.