Three suspected Al Qaeda terrorists who carried out twin attacks in a Saudi Arabian oil city, killing 22 people, including eight Indians, were allowed to walk free as part of a deal to ensure the release of others taken hostage by them, a media report said on Tuesday.

Also Read Saudi hostage drama ends

The official Saudi line was that three of the four kidnappers broke out of the compound using human shields after they staged the brutal rampage during the weekend in Al-Khobar city.

But one employee of the residential complex, where the hostage drama took place, told a different story, claiming that the Saudi forces let them out after they began killing hostages and threatened to blow themselves up, The Times
newspaper reported.

A hostage heard the gunmen shouting that they would release the captives if the security forces let them go, it said.

"The security forces refused at the beginning but then apparently relented. There was a kind of deal reached, although some hostages had already been killed," the employee said.

Quoting sources, the report said the kidnappers escaped shortly before Saudi commandos landed on the building.
 
"It is believed that the three left by foot and didn't hijack any vehicle until they were outside the compound," a source said. "To leave, they had to puncture three cordons of defence."

One European was decapitated and his head thrown out of the window, another source said. A kidnapper was said to  have threatened to shoot a baby in front of its mother.

A Scotland Yard anti-terrorist squad flew to Saudi Arabia on Monday to advise the Saudis and prepare a report for a British coroner on the murdered oil executive Michael Hamilton.