SANA'A: Thousands of citizens fled the Yemeni capital Wednesday to escape gunbattles between loyalists and opponents of President Ali Abdullah Saleh, who said he would make no more concessions to those seeking his ouster. Sporadic machinegun fire rang out for the third day in the sandbagged streets around the mansion of an influential tribal leader who has backed protesters seeking to overthrow the longtime ruler after repeated international mediation failed. Black smoke rose from the compound of Sadiq Al-Ahmar, at the center of the clashes that have killed more than 40 people since Monday, when his guards first exchanged fire with loyalist forces they accused of stockpiling weapons at a nearby school. Authorities closed Sana'a airport and flights were being diverted after clashes broke out with tribesmen loyal to Ahmar, a security official told Reuters, adding that some airlines had begun canceling flights to Yemen Tuesday. “What happened was a provocative act to drag us into civil war, but it is limited to the Ahmar sons. They bear responsibility for shedding the blood of innocent civilians,” Saleh told selected media including Reuters. “Until this second, they are attacking the Interior Ministry. But we don't want to widen the confrontation,” he said. “They have chosen this and they made the wrong decision to confront the state with this kind of violence.” Four people were killed and 11 wounded, the defence ministry said, blaming Ahmar's men. Witnessess and officials said Ahmar's backers took over several ministry buildings near his compound. The fighting, the most sustained clashes in Sanaa since protests against Saleh's rule began in February, erupted on Monday, a day after the president refused at the last minute to sign a Gulf-brokered deal that would ease him out of power. Saleh has backed out twice before, but Sunday's turnabout, after loyalist gunmen trapped Western and Arab diplomats in the United Arab Emirates embassy for hours, appeared to have sparked a major reaction. Gen. Ali Al-Mohsen, a regional army commander who has sided with protesters, called on the armed forces to defy Saleh. “Beware of following this madman who is thirsty for more bloodshed,” Mohsen said in a statement. Both sides blamed each other for the violence, which the opposition said could start a civil war. The bloodshed dimmed prospects for a political solution to a popular revolt. “I think there's a real risk that violence can escalate, and we see a move towards low intensity civil war,” said Shadi Hamid, analyst at the Brookings Doha Center.