GENEVA — The International Committee of the Red Cross (ICRC) said Sunday fighting in Syria has become so widespread that the conflict is now in effect a civil war. The change in status means combatants will now be officially subject to the Geneva Conventions, leaving them more exposed to war crimes prosecutions. The Red Cross had previously regarded only the areas around Idlib, Homs and Hama as war zones. In Damascus, regime officials are disputing claims that they used heavy weapons in fighting on Thursday. Activists initially described fighting in the village of Treimsa near Hama as a massacre of dozens of civilians, but later accounts suggested most of the dead were armed rebels. The UN accused Syrian forces of using heavy artillery, tanks and helicopters, but Damascus denied those allegations and said just two civilians had been killed. The accusations, if proved, would mean Damascus had broken an agreement it made with envoy Kofi Annan. Later on Sunday, video footage emerged purporting to show heavy fighting in southern Damascus. Activists claimed the fighting was the most intense seen in the capital since the start of anti-government protests in March last year. “The regular army fired mortar rounds into several suburbs” where rebels of the Free Syrian Army are entrenched, said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights. “They have never been this intense,” he said. The fighting was heaviest in the Tadamon, Kfar Sousa, Nahr Aisha and Sidi Qadad neighborhoods, he said. There has been no independent confirmation of their claims. Meanwhile, Iran, the main regional ally of Syria, said it was ready to host a meeting between Damascus and its opponents aimed at solving the country's conflict. “Iran is ready to host the Syrian opposition for dialogue with the Syrian government,” Foreign Minister Ali Akbar Salehi told Arabic-language Al-Alam television. “We believe that the Syrian issue should have a Syrian solution,” he said, reiterating Iran's stance. Tehran has repeatedly offered to help resolve the crisis, but this has been rejected by Syria's opposition and Western and Arab states which accuse it of militarily aiding President Bashar Al-Assad's regime to suppress a rebellion. — Agencies