Syrian security forces continued to clash with rebels Friday, while U.N. diplomats condemned the Syrian government and criticized the Security Council for their roles in the country's 17-month uprising.

Activists say Syrian troops stormed opposition strongholds in the suburbs of Damascus and shelled some neighborhoods in the northern city of Aleppo, Syria's commercial hub.

The London-based Syrian Observatory for Human Rights said that about two dozen people were killed in unrest Friday.

The U.N. General Assembly approved a non-binding resolution that condemns Syria's use of heavy weapons in the fight against rebel forces. The vote also criticizes the U.N. Security Council for failing to stem the violence.

Syria blasted the General Assembly's action.

The country's U.N. ambassador, Bashar Ja'afari called the resolution a “piece of theater” that would have no impact on the country.

U.N. chief Ban Ki-moon said the Syria conflict is now a “proxy war” and he urged major powers to end the violence. He said “the immediate interests of the Syrian people must be paramount over any larger rivalries of influence.”

Russia and China have vetoed three Security Council resolutions on Syria. Mr. Ban said the Council has become “paralyzed” over the issue.