Cairo, Dhu-AlHijjah 24, 1437, Sep 25, 2016, SPA -- At least 231 civilians have been killed in violence in Syria's embattled city of Aleppo and its outskirts since a truce collapsed this week amid an intense air campaign by the government and allied Russia against rebels there, a monitoring group said. The toll included 23 civilians killed in air bombing targeting the rebel-held eastern section of Aleppo since Saturday night-time, Rami Abdel-Rahman, the head of the Syrian Observatory for Human Rights, told dpa on Sunday. Aleppo in northern Syria has witnessed in recent days the heaviest airstrikes since the country's conflict began in 2011. The surge in violence has worsened the situation inside eastern Aleppo, which has been besieged by government forces since July 17. Jets on Sunday resumed pounding rebel-held areas in Aleppo, ending a lull of hours there, the Observatory said. Opposition fighters recaptured Handarat, a refugee camp on the northern edge of Aleppo, on Sunday, a day after they lost it to regime forces. Handarat is located near Castello Road, a major supply route to opposition areas in eastern Aleppo. Once Syria's commercial hub, Aleppo has been divided between government forces in the west and rebels in the east since fighting erupted for control of the city in mid-2012. UN envoy on Syria, Staffan de Mistura, called Sunday on Washington and Moscow to salvage the ceasefire that they brokered earlier this month as part of an ambitious agreement to end fighting in Syria. The truce went into effect across Syria on September 12, but crumbled on Monday following a deadly attack on an aid convoy near Aleppo. -- SPA 22:44 LOCAL TIME 19:44 GMT www.spa.gov.sa/w