WASHINGTON, April 13 (Xinhua) -- Senior U.S. security officials said on Friday the attack in Syria's capital Damascus targeted several sites as well as the Syrian government.

U.S. Chairman of the Joint Chiefs of Staff Joseph Dunford said on Friday that the attack had multiple targets in Syria, including a scientific research center in greater Damascus area, a chemical weapon storage facility west of Holmes and a facility in the second target.

The first target was a military facility for Syrian research and development of chemical and biological warfare technology; the second was assessed as a primary location of Syrian sarin equipment and the third contains a chemical weapons equipment storage facility and an important command post, he said.

The air and naval forces of three Western nations -- the United States and its European allies Britain and France -- were involved in the operation, he said.

This attack is "qualitatively and quantitatively" different from the U.S. unilateral attack against Syria last April, as it came this time "with two allies on multiple sites, which will result in the long-term degradation of Syria's capability to research, develop and deploy chemical and biological weapons," he also said.

U.S. Defense Chief James Mattis also said in a briefing that the attack targeted the Syrian government directly.