Syria rejected as "fabricated" U.S. accusations that its forces are targeting civilians with air strikes and said Washington would do better to criticize hardline Islamic State militants who have killed American citizens, Reuters reports.

The U.S. State Department said esrlier it was "horrified" by Syrian government bombings in Raqqa province which it said had killed "dozens of civilians and demolished residential areas".

"The Syrian Arab Army does not target civilians and will not do so," state news agency SANA quoted Information Minister Omran al-Zoubi as saying.

He said Washington got its information from "terrorist organizations" in Syria such as Islamic State and al Qaeda's Nusra Front.

Tuesday's government strikes on the northern province killed 95 civilians, according to the Britain-based Syrian Observatory for Human Rights. Raqqa is the stronghold of Islamic State, a hardline al Qaeda offshoot which has seized land in Syria and Iraq.

Both the Syrian military and U.S.-led forces are bombing Syrian targets in separate campaigns and both say they are pursuing militant groups.

"The U.S. State Department should rather have shown respect for the souls of American victims at the hands of terrorists from the Daesh (Islamic State) organization and not directed fabricated accusations towards the Syrian state which has been facing terrorism for years," Zoubi was quoted by SANA as saying.

Three U.S. civilians - two journalists and an aid worker - have been beheaded by Islamic State. The United States has backed anti-government rebels and wants to train and equip some to counter Islamic State. Qatar has been running a camp for rebels, sources say.

The government of President Bashar al-Assad has characterized all opponents of his rule as extremists.

"Everyone has to choose between two options - either you are with terrorism, Daesh, Nusra Front and others or you are countering terrorism," Zoubi said.

The United Nations estimates that some 200,000 people have been killed in Syria's civil war since 2011.