Israeli researchers have developed a portable device that causes excruciating sensations of burning and can be built for just $250,000, raising fears that even the world's poorest, most oppressive governments will now be able to use advanced non-lethal weapons on their civilian populations.

The Man-Portable Active Denial System, developed by researchers at the College of Judea and Samaria, can beam a microwave ray that causes skin surface to heat up to 130 degrees Fahrenheit, causing the nerve cells in the skin to think they're on fire.

In tests of a similar project by the US military, "nobody [was] able to stay in the beam for more than a few seconds," writes David Hambling at Wired.com.

Reports of the US military developing a burn ray have been around for some time, but the US's Active Denial System is a nine-ton machine that has not yet come out of testing, for technical and political reasons, Hambling reports.

But the Israeli researchers say they have developed "unique know-how" that allows them to build the technology on a much smaller scale, and for much less money. A cheap, portable version that could be easily purchased and distributed to law enforcement agencies raises concerns about civil rights, particularly in the wake of numerous controversies about police use of Tasers.

Steve Wright, a security expert at Leeds Metropolitan University in the UK, described the new class of "active denial" weapons as "torture at the touch of a button."

"The project highlights how other countries could now develop their own versions on a shoestring budget," Hambling writes. "If a university department can do it in Israel, so can others in Russia, China or anywhere else."

Neal Ungerleider, on his TrueSlant blog, notes that Human Rights Watch has declared active denial weapons to have limited military applications.

And while the US military has been very cautious in the development of its version of the technology, Ungerleider suggests that the Israeli government may be more willing to experiment, pointing out that it has previously used "skunk bombs" on protesters. Skunk bombs spray their targets with a viciously foul-smelling liquid that can't be washed off for at least 48 hours.

In 2004, defense contractor Raytheon received permission from the FCC to demonstrate early versions of active denial weapons to "law enforcement, military and security organizations," suggesting that the US foresees allowing the technology into the hands of private security contractors.