The United Nations Children's Fund says it is "extremely" concerned for the safety and wellbeing of children caught up in the violence engulfing the northern Syrian city of Aleppo, including the eastern neighborhoods under government siege.

In a statement Wednesday, UNICEF regional director Saad Houry called for unhindered humanitarian access to the divided city and for children to be protected. UNICEF says that children make up a third of the 300,000 residents trapped in rebel-held besieged neighborhoods.

In the western, government-controlled areas, UNICEF says 25,000 people have been displaced and are taking shelter from intense fighting in mosques, university campuses and public gardens.

Aleppo has witnessed fierce fighting recently. Government troops encircled rebel-held areas of the city on July 17, making it one of the largest besieged areas in Syria