The prospects for a truce in Syria are dimming by the day as Russian warplanes keep up their brutal bombing in support of the Assad dictatorship.

In a video that surfaced online, a little boy waved his hand from beneath the rubble of a shattered building, telling rescue workers he was still alive. Seconds later they freed him, bloodied but still breathing.

In another they dug frantically for a baby, but it was too late when they got to the child.

CBS News can't independently verify the videos, but they appear to show the Syrian regime's new offensive in Aleppo Province, which is backed by Russian airstrikes.

Hassan Haj Ali is a rebel commander who told us his men have received weapons from the U.S. and are trying to fight off the assault.

"When the regime kills women and children," he said, "they're telling Syrians to get out of rebel-held areas."

As the regime and Russia bombard Aleppo Province, the battlefield there has become even more chaotic. Now there's evidence that groups supported by the U.S. have started to fight each other as they vie for territory.

Hassan Haj Ali, along with other U.S.-backed commanders, said they're clashing with Kurdish fighters -- and the Kurdish group also receives American support.

Hassan Haj Ali, a Syrian rebel commander CBS News

"Our American friends said they'd put pressure on the Kurds to stop the clashes," he told us, "but there's no sign that's happened."

The glimmer of good news from Syria is that aid convoys carrying food and medicine made it to areas besieged by fighting on Wednesday. One of those towns is Madaya, where there have been reports of people starving to death.