国际英语新闻:US Special Forces Kill IS Commander in Syria, Capture Wife

Yan St-Pierre, the CEO of Berlin-based security consulting firm MOSECON, said the U.S.announcement of the raid was intended to deliver a psychological blow to the Islamic State to slow its momentum.

"Usually, these announcements don’t come within a few hours of the kill being executed. Rather, maybe a day later. They want to confirm that the target was indeed killed," St-Pierre told VOA. " ... But over the past 24 hours, past 48 hours, with ISIS making so much progress, it probably added to the pressure of having to act quicker than they wanted."

The oil field raid overnight came after Islamic State militants had gained ground in Iraq, raising their black flag over the city of Ramadi on Friday.

Still, St-Pierre said, the operation was most likely planned well before the most recent IS offensive and appeared to have been successful from a military standpoint. In Washington, Defense Secretary Ash Carter said in a statement that the operation was "another significant blow" to the Islamic State group.

But it was unclear how much harm the operation will cause the Islamic State.

"With the exception of the top leadership, they seem to be able to replace people in these capacities pretty easily," said Michele Dunne, senior associate at the Carnegie Endowment for International Peace.

Syria claims attack

Syrian state media said its government forces also targeted IS militants in the al-Omar area east of Deir al-Zour, killing a "large number" of fighters and a senior Islamic State leader. It identified a commander killed as Abu al-Teem al-Saudi, a national of Saudi Arabia.

The Britain-based Syrian Observatory for Human Rights confirmed an oil field attack but did not attribute responsibility for the 19 people it said had been killed there.

The Islamic State group took control of major oil fields in Syria in July, when militants overran northern and eastern sections of the country.