That brought to four the number killed in clashes with security forces in Aden on Friday. Dozens were wounded.

Twenty-one people have now been killed since Feb. 17 in daily protests against President Ali Abdullah Saleh’s 32-year rule. Unrest has been especially intense in the once-independent south, where many people resent rule from the north.

Loyalists and opponents of the 68-year-old leader held rival demonstrations in the capital Sanaa after Friday prayers.

Anti-Saleh protesters shouted slogans which have echoed around the Arab world since the uprisings in Egypt and Tunisia: “The people demand the downfall of the regime.”

Saleh supporters chanted their loyalty to a man they see as holding the impoverished tribal nation together. “The creator of unity is in our hearts. We will not abandon him,” they cried.