A powerful explosion hit Syria's northern city of Aleppo on Friday, close to the ruling party headquarters, the Syrian Observatory for Human Rights said.

"A big explosion was heard near Al-Jabiri Square," the group said in a statement.

"Initial details indicate that the Aleppo blast was targeting the local branch of the ruling Baath party and there is no information until now on the number of victims that fell in the explosion," the group added.

[Source: Reuters and AFP]