A plane with U.S. soldiers wounded in a deadly attack on their helicopter in Iraq arrived early Monday in Germany, bringing them for treatment at an American military hospital, a spokesman said.

About 18 of the 30 wounded aboard were believed to be casualties of Sunday's strike that also killed 16 soldiers when their Chinook helicopter (search) was shot down outside Fallujah, said Maj. Mike Young of the U.S. 86th Airlift Wing based in Ramstein.

He said the exact count would be determined after the entire planeload of wounded was brought to nearby Landstuhl Medical Center (search), the biggest U.S. military hospital in Europe.

Of the nearly 30 soldiers who arrived aboard the C-17 transport in a predawn rain, 14 were taken to a waiting ambulance bus on stretchers while the others walked.

Young said he had no immediate details on the condition of those wounded in the Chinook attack.

The helicopter was carrying dozens of soldiers heading for leave outside Iraq when insurgents hiding in a date grove shot it down with missiles, witnesses said.

The death toll was the highest for U.S. troops since March 23 -- the first week of the invasion that ousted Saddam Hussein (search) -- and the attack represented a major escalation in the campaign to drive the U.S.-led coalition out of the country.