The protests marked the fourth anniversary of a Feb. 11 uprising that eventually ended the autocratic rule of longstanding President Ali Abdullah Saleh.

Thousands of Houthi supporters gathered at the city's center to mark the passing of four years since the revolution.

Many demonstrators chanted anti-U.S. and anti-Israel slogans.

The Houthi group's opponents, meanwhile, staged their own rallies on the streets of the capital to mark the revolution anniversary.

They chanted anti-Houthi slogans and condemned a controversial "constitutional declaration" issued last week by the Houthi leadership.

Last Friday, the Houthis issued a "constitutional declaration" dissolving parliament and establishing a 551-member "transitional council" to temporarily run the nation's affairs.

The declaration, however, was rejected by most of Yemen's political forces – along with some neighboring countries – which described it as a "coup" against "constitutional legitimacy."

Late last September, the Houthis seized control of Sanaa and have since sought to expand their influence to other provinces farther afield.

On Wednesday, Houthi militants attacked activists participating in anti-Houthi rallies in Sanaa, according to eyewitnesses.