One protester was killed and another injured when the army fired at a protest in Yemen's northern province of Amran, dpa reported according to officials.
An unconfirmed report from Al-Arabiya broadcaster spoke of two dead and nine injured.
The protesters had gathered in Harf Sufian district calling for the ouster of President Ali Abdullah Saleh and his regime.
A member of the Shiite Houthi rebel groups said scores of protesters were injured when the army shot at the demonstration.
In the capital Sana'a, tens of thousands of anti-government protesters gathered in front of Sana'a university, also calling for the ouster of Saleh.
Yemen's protesters have been inspired by uprisings in Tunisia and Egypt, which have resulted in the overthrow of their long-time presidents.