The Transportation Security Administration (search) announced that, starting next week, all airline passengers must take off jackets before passing through metal detectors. Also, more travelers will be subjected to pat-down searches and checks for explosives. U.S. officials got a wake-up call last month about the need to screen passengers for explosives when two Chechen women apparently carried bombs onto two Russian planes and blew them up.

Bags checked onto planes in the United States must pass through machines that can detect various kinds of explosives. But neither the walk-through metal detectors that passengers use on the way to gates nor the X-ray machines for carryon bags can detect plastic explosives.

Rafi Ron (search), former head of security at Israel's Ben Gurion Airport (search) and now a security consultant in Washington, said the steps were "something we've been expecting for too long, but finally it's coming."

Screeners will advise passengers of the new procedures when they put their carryon bags on the conveyor belt, agency spokeswoman Yolanda Clark said.

Every passenger selected for secondary screening after passing through metal detectors will have their carryon items subjected to checks by explosives trace detectors.

Screeners also have more discretion to conduct pat-down searches and check carryon bags for bombs.

Air Travelers Association (search) President David Stempler said the changes are a good idea, though some passengers could be upset by hand searches.

"Given the extraordinary need for it — given the recent bombing of the planes in Russia, heightened security alerts, tension leading up to the election — I think these are necessary evils that passengers have to put up with," he said.

The Sept. 11 commission recommended in its final report that the government make it a priority to improve the ability to detect explosives on passengers at security checkpoints.

"As a start, each individual selected for special screening should be screened for explosives," the report said.

The agency also is testing walk-through bomb-detection machines at five airports. Document scanners that can pick up explosives residue on boarding passes and IDs are being tested at Washington Reagan National Airport (search).