An F/A-18F Super Hornet lands aboard the aircraft carrier USS George H.W. Bush in the Persian Gulf on Tuesday, Sept. 23, 2014, after conducting strike missions against Islamic State group targets in Syria.

Despite claims by activists that U.S. and allied Arab airstrikes killed up to two dozen civilians this week in Syria, a Pentagon official said the initial damage assessment did not confirm any civilian casualties.

Army Col. Steve Warren, a Pentagon spokesman, said military intelligence is still incomplete, but the before and after imagery of the Islamic State and al-Qaida sites hit by missiles and bombs did not show any civilians.

“We took all available mitigating actions to reduce civilian casualties," he said. "Right now we believe there were no civilian casualties.”

Asked whether videos posted on social media sites that show workers trying to save civilians trapped under rubble were faked, Warren answered, “Yes.”

“We come to that statement by examining our battle damage assessment up until now,” Warren said.

In Syria, estimates varied of how many civilians were killed, from eight to 24.

Video showing people picking through flattened buildings emerged Tuesday after heavy airstrikes damaged or destroyed what the Pentagon said were militants' training camps, weapons caches and command and control centers in northern and eastern Syria.

The strikes, which also involved warplanes from five Sunni Arab states, struck Islamic State targets in and around Raqqah, Dair Alzour, Hasakah and Abu Kamal. The Pentagon said about 200 bombs were dropped, and 47 Tomahawk cruise missiles were fired from Navy ships.

But some of the salvos targeted partners of al-Qaida-linked Nusra Front, which makes getting to the truth complicatesd. Unlike Islamic State, Nusra enjoys wide support among Syrian rebels and civilians living in areas it controls.

That region in northwestern Syria, called Idlib province, has already suffered three years of civil war between antigovernment rebels and President Bashar Assad's security forces.

Antigovernment activists said five of the Tomahawk missiles struck in Idlib province, four on Nusra Front bases and weapons warehouses, and the other in the village of Kafar Daryan.

The Syrian Network for Human Rights said 12 people were killed in the village, including four children in one family.

Fadel Abdul Ghany, head of the Syrian Network for Human Rights, which tallies daily death tolls and other data of the Syrian conflict, said he was contacted Tuesday by the U.S. State Department’s Bureau of Democracy, Human Rights, and Labor and asked about reports of civilian deaths.

He said he sent a report identifying civilians reported killed in Dair Alzour and elsewhere. But he said he could not provide photographs, videos or other evidence because the towns are controlled by Islamic State.

The State Department took the information and didn’t respond, he said.

“It’s in the American’s interest to hide it,” he said Wednesday after the Pentagon denial of civilian casualties. “The reality is there are civilians and there are fighters” among the dead.

A spokeswoman for the Bureau of the Democracy, Human Rights, and Labor would not comment on the report, but said the State Department takes any allegation of civilian casualties seriously.

"We have seen reports on social media and from human rights activists alleging civilian casualties but are not in a position to confirm the reports at this time," said the spokeswoman, who asked for anonymity because she said she was not authorized to speak on the record. "Before any mission, every precaution is taken to ensure civilians are not harmed. Regardless, we take seriously any of loss of life and will look into this matter further."

Hennigan reported from Washington and Abdulrahim reported from Irbil, Iraq.

©2014 the Los Angeles Times. Distributed by McClatchy-Tribune Information Services.