As violence rages close to the Syrian capital, a U.N. convoy heads to Douma.<br/> <br />Smoke rose from the city where international observers visited hospitals Tuesday.<br/> <br />Amateur video posted online Monday appeared to show an attack by government forces on the city.<br/> <br />Helicopters also participated in the onslaught for the third day, according to one activist.<br/> <br />Reuters cannot verify the content of the video.<br/> <br />A Syrian officer said he did not guarantee the safety of the observers in the area.<br/> <br />The full U.N. mission was suspended in mid-June over concerns for the safety of monitors, but limited humanitarian operations continue as world leaders struggle to resolve the crisis.<br/> <br />Lindsey Parietti, Reuters
