Veteran war surgeon Jacques Beres has his own compelling reasons for urging that a no-fly zone be imposed over Syria -- one bomb dropped by the regime leaves more wounded than doctors can fix in a day. Working under cover in the northern city of Aleppo, which has been pounded for weeks as President Bashar al-Assad\'s forces seek to overrun rebel bastions, Beres insists the death toll in the Syrian conflict is higher that what is reported. \"At least 50,000 people have been killed without counting the disappeared,\" Beres, a French surgeon who daily patches up dozens of people in a hospital near the front lines of Aleppo, told AFP in an interview. The Syrian Observatory for Human Rights, which has a network of activists on the ground across Syria, has given a latest toll of at least 26,283 people killed in Syria since the revolt began in March last year -- 18,695 civilians, 1,079 defectors and 6,509 troops. But Beres said watchdogs such as the Britain-based Observatory are unable to paint a full picture of the losses because many deaths are documented \"only with ink and paper.\" \"I am sure that the dead that I have here are not tallied in London,\" said Beres. In the past two weeks, he said, he has treated a daily average of 20 to 45 wounded people, the majority of them fighters with the opposition Free Syria Army, including \"quite a few jihadists.\" Fatalities in rebel ranks range between two and six each day, he said. But those are just the figures collected in one small hospital within a massive commercial city which is now almost evenly divided between rebel and army-controlled areas. Many gray zones lie between both camps and the security situation remains fluid: shops open and pedestrian traffic has resumed in some neighbourhoods while tank shells and mortar hit others. \"It is shameful that a no-fly zone hasn\'t been set up,\" said the co-founder of Doctors Without Borders, setting aside a cup of tea to review X-rays and offer a Syrian colleague advice on how best to dislodge a bullet from a man\'s leg. \"It is an incredible massacre. Even if now it is a civil war, it is a very asymmetric conflict: light weapons against tanks and aerial bombardment,\" said Beres, whose experience on the field covers almost every major war from Vietnam in the sixties to Libya last year. \"All this because they asked for a little bit of freedom and said that they had enough of Bashar.\" This is the third humanitarian mission that Beres has undertaken to Syria this year, backed variously by organisations such as France Syrie Democracie, UAM93, Doctors Without Borders, and AAVS (Association d\'aide aux victimes en Syrie). He was in the central city of Homs in February when the neighbourhood of Baba Amro was decimated by Assad\'s forces. In May he roamed around Idlib province where he says pro-regime soldiers destroyed pharmacies and burned a clinic down to the ground. Beres, in his seventies, has been smuggling himself into the country at great risk, armed only with the firm belief that he has a \"humanitarian duty to heal\" even though \"in one second a bomb leaves more people wounded than a surgeon can fix in a day.\"