The Trump Administration imposed economic sanctions against Syrian government chemists and other scientists on April 24 for their role in the alleged sarin gas attack in early April that killed dozens of people.

The sanctions were leveled against 271 employees of the Scientific Studies & Research Center, the Syrian government body the U.S. believes is responsible for developing and producing chemical and biological weapons. The action directs U.S. banks to freeze any assets the individuals may have and bans American companies from conducting business with them.

Those targeted all have expertise in chemistry and related disciplines. They have supported the regime’s chemical weapons program since at least 2012, according to the U.S. Treasury Department’s Office of Foreign Assets Control, which released a list of their names.

These government employees are “highly educated” chemical specialists who are likely to be able to travel outside of Syria and use the international financial system, Trump Administration officials said.

“These sweeping sanctions target the scientific support center for Syrian dictator Bashar al-Assad’s horrific chemical weapons attack on innocent civilian men, women, and children,” Treasury Secretary Steven T. Mnuchin said in announcing the action at the White House.

The U.S. and several Western allies claim Assad is responsible for unleashing sarin gas, a deadly nerve agent, in the rebel-held town of Khan Sheikhoun on April 4. The UK-based Syrian Observatory for Human Rights monitoring group said 86 civilians were killed. Assad has called the incident a fabrication.

The Treasury Department will work with State Department officials to “relentlessly pursue and shut down the financial networks of all individuals involved with the production of chemical weapons used to commit these atrocities,” Mnuchin added.

After the attack, the U.S. retaliated a few days later by launching cruise missiles against a Syrian air base the Pentagon says was used to launch the chemical attack.

The Treasury and State departments also targeted 18 senior Assad regime officials and five branches of the Syrian military in January after a United Nations inquiry concluded that the government was responsible for three chlorine gas attacks against civilians in 2014 and 2015.

Source: cen.acs.org