Thieves have stolen several F-16 fighter-jet engines from an airbase in central Israel, local media outlets reported Thursday.

An initial investigation suggested that the thieves may have been assisted by base personnel, either military or civilian, the Walla news website said.

It was unclear how many of US-made engines, each worth millions of US dollars, were stolen.

The report said each of the turbofan engines weighs several tons as investigators suspect that metal thieves are likely behind the initiative.

But military police have not ruled out involvement of weapon dealers or terror-related elements in the theft, Israel National News reported on its website.

A military spokesman declined comment on the incident, according to Army Radio.

In June last year, eight engines that power F-15 and F-16 jets were stolen from the northern Ramat David airbase. Police later discovered parts of the engines in a warehouse used by scrap metal merchants.

Military officials described the security breach at the base as "scandalous."

Metal thieves have also targeted other Israeli military installations in the past year.