Unrest has left one demonstrator dead in Yemen's south after the unraveling of a deal that would have eased Yemeni President Ali Abdullah Saleh out of power.
Officials say the army opened fired on protesters in the port city of Aden Monday, killing one demonstrator.
Activists and medics say at least two protesters were killed in Aden Saturday as security forces moved in to clear a square they had occupied. They are demanding the immediate removal of Mr. Saleh from office.
At least 140 people have died in the unrest since January.
Meanwhile, Gulf officials said Sunday they are sending a top official back to Yemen to try to salvage the deal after Mr. Saleh refused to sign the agreement.
Officials with the six-nation Gulf Cooperation Council, which sponsored the accord, said the deal's signing ceremony had been postponed indefinitely.
They said Mr. Saleh had agreed to sign the deal as leader of the ruling General People's Congress party but not in his capacity as president - as required by the deal.
The Yemeni president had been expected to sign in advance of a formal ceremony in Riyadh planned for Sunday or Monday.
The GCC plan called for President Saleh to hand over power to a deputy and resign within 30 days of signing the initiative. It would establish a unity government that would include opposition members. A presidential election would take place two months after Mr. Saleh leaves office.
Both the opposition and Mr. Saleh said last week that they agreed to the deal.
Some information for this report was provided by AFP.