The situation in Aleppo, Syria, has escalated in recent days. Government troops have cut off the eastern part of the city, which is under the control of rebels, from transport routes.
Local people, about 300 thousand, were blocked; they are short of food and medicine. On Sunday, opposition groups began a counter-attack to break the siege.
According to the Syrian Observatory for Human Rights, at least 28 people were killed in attacks by rebels and dozens were injured during last 24 hours.
In response, forces of President Bashar al-Assad and forces of Russia intensified air strikes on areas controlled by the opposition. Local residents burn tires to create a smoke screen against for aircraft.