"The escalation of violence in the past few days is extremely alarming especially given that the government and the opposition were so close to an agreement," spokesman Robert Colville told a press conference.
"We are deeply concerned that the government may be pushing the country close to the brink of civil war."
"We received reports of dozen of casualties, including women and children, during fighting in the past few days and we are trying to confirm these reports," Colville said.
"We call on the government to stop the disproportionate use of force against peaceful demonstrations ... to stop detaining activists, human rights defenders and journalists and (to) investigate all allegations of crimes by security forces."
Colville said Sanaa had authorised the commission to send a mission to Yemen in June, but added, "We are seeking access earlier than that and we are continuing discussions with the governement on the terms of reference of that mission."
Saleh, who has been in power for 33 years, has faced protests since January calling for his departure, which he has met with force.
Fighting broke out between loyalists of opposition tribal chief Sheikh Sadiq al-Ahmar on Monday, a day after Saleh refused to sign a Gulf Cooperation Council-sponsored accord that would have seen him cede power within 30 days in exchange for immunity from prosecution.
Instead, Saleh issued fresh demands, including that the opposition sign the deal in his presence, and warned of civil war.
Ahmar said on Friday that a truce was in place between his fighters and security forces in Sanaa after deadly clashes earlier in the day, but he is ready for war if the embattled president wants one. (*)
Editor: Kunto Wibisono
Copyright © ANTARA 2011
