Damascus, May 5 (IANS): At least 13 people were killed and many more wounded by a fresh rebel shelling on government-controlled areas in the northern city of Aleppo, media reported.

Improvised rockets hit residential buildings in the Mogambo district west of Aleppo on Monday evening, destroying many buildings, said Xinhua report, adding that at least three people were killed and tens of others wounded.

The work was underway to help the people who are stuck under the rubble.

Ten other civilians, mostly children, were killed on Monday by similar shelling on other government-controlled districts of Aleppo city.

The rebels in the eastern part of Aleppo city have recently intensified their shelling on government-controlled areas in the western part of that battered city.

The recent shelling, however, was marked with the rebels' use of heavy rockets due to the big size of destruction they are leaving.

Last month, many people were killed and entire building blocks were reduced to rubble when heavy improvised rockets slammed the al-Aziziyeh district of Aleppo.

The opposition activists also accuse the government troops of dropping barrel bombs on rebel-held area in that city, which was once called the economic hub of Syria and economy powerhouse.

A day earlier, the Syrian Observatory for Human Rights said a Syrian government helicopter struck a school with a barrel bomb in Aleppo, killing at least seven civilians, including children.

According to the Observatory, the school is located in Saif al- Dawla, a district where control is split between the government forces and jihadist groups.