Israeli airstrikes hit a copper smelting factory in Aleppo, Syria, killing several people, Syrian media outlets reported on Sunday.

Initial reports indicate that a factory is burning in Syria's second city Aleppo after an airstrike.

The Syrian Observatory for Human Rights war monitor said in a statement that 12 people were killed in the airstrike.

It also said that three explosions occurred one after the other.

However, official Syrian sources did not give any specific numbers, but only said 'several'.

The Israeli side had no comment to confirm.