SAN'A, Yemen—A small anti-government protest turned violent in the Yemeni capital Saturday, according to eyewitnesses, with demonstrators—emboldened by Friday's massive protests in Egypt—clashing with security forces.

At least nine protesters were set upon by police with batons when security forces blocked up to a hundred demonstrators as they attempted to march to the Egyptian Embassy here, in a show of solidarity with protesters in Egypt, according to eyewitnesses.

It was the first instance of reported violence during a recent bout of protests in Yemen, which started earlier this month in the wake of anti-government demonstrations in Tunisia that eventually ended the long rule of that North African country's autocratic ruler.

Witnesses also said prominent human-rights activist Abdul Hadi al-Azazi was arrested in the march on Saturday.

A Yemeni governmental spokesperson, Tareq Al-Shami, said: "Security forces were not involved, but because protesters were both pro-government and anti-government, clashes could have taken place among them, with security forces out of the picture."