WASHINGTON -- Bottles of the popular herb ephedra should bear warning labels that the pills can cause heart attacks, strokes or even kill, the Food and Drug Administration said Friday.

The FDA proposed the warning labels -- reviving an attempt the powerful dietary supplement industry had blocked for years -- while saying a ban on at least some ephedra-containing products remains under discussion.

The action came less than two weeks after a medical examiner announced the heatstroke death of Baltimore Orioles pitcher Steve Bechler was probably linked to his use of ephedra. The FDA, which has reports of at least 100 deaths linked to ephedra supplements, had been under pressure from doctors for years to ban the herb -- but Bechler's death renewed the scrutiny.

"Throughout America, there continue to be tragic incidents that link dietary supplements containing ephedra to serious health problems in consumers that use these products,'' said Health and Human Services Secretary Tommy Thompson.

"I don't know why anyone would take these products. Why take the risk?''

The FDA is now seeking public comment on the warning labels. Thompson suggested that FDA could take further regulatory action, but stopped short of calling for an outright ban. "Dietary supplements containing ephedra may present a significant and unreasonable risk of illness and injury,'' he said.

The FDA said it had warned 24 companies that target the amphetamine-like stimulant to athletes and bodybuilders that there is no scientific evidence that ephedra helps athletic performance -- letters that signal the government is considering a bigger crackdown.

The FDA also released results of a long-awaited ephedra review by the Rand Corp., which concluded the herb probably has killed at least occasionally, while giving users very little weight-loss benefit.

"The current scientific evidence strongly suggests that at least some ephedra products present an unreasonable risk,'' said FDA Commissioner Mark McClellan.

Anticipating the announcement, a leading ephedra manufacturer, Metabolife International, issued a statement condemning "irresponsible marketing practices'' that result in athletes misusing the product and called for limited government regulations such as banning sales to minors.

"I believe it is imperative that consumers continue to have the choice to use these beneficial weight-loss products, safely and effectively, as millions have done, in their battle to control and maintain their weight,'' said David Brown, president of Metabolife.

Ephedra has been linked to life-threatening side effects, even when used by outwardly healthy people at recommended doses, because it speeds heart rate and constricts blood vessels. Those effects can be exacerbated by exercise and use of other stimulants such as caffeine, and they're particularly risky if the user has certain underlying medical conditions such as heart disease.

Canada has long warned consumers not to use ephedra, and it has been banned by the NFL, NCAA and the International Olympic Committee. Earlier this week, baseball imposed a ban on those players with minor league contracts.

"Hopefully, there's more coming. It's a start,'' Jim Beattie, the Orioles' executive vice president of baseball operations, said of the FDA action.

The Orioles are on record for calling for a ban on ephedra by Major League Baseball.

Because ephedra is an herb, U.S. law lets manufacturers sell it over the counter with little oversight to ensure safety. The FDA must prove a clear danger to public health to curb sales.

Manufacturers blocked a 1997 FDA attempt to restrict sales of certain doses by arguing the agency lacked enough proof of danger. More recently, companies have intensely lobbied the Bush administration to settle the controversy with warning labels that urge consumers to consult a doctor before using the herb.

The FDA first proposed stronger warning labels in 1997. On Friday, it reopened that proposal for public comment -- a step required before the agency can mandate the warnings. The proposal suggests every ephedra bottle list death, heart attacks and strokes as potential side effects, and caution consumers about exercise, caffeine and people who should never use the herb.

The FDA said Friday it will seek public comment on whether ephedra poses enough risk to justify banning a dietary supplement -- leaving in question just how big a crackdown the agency intends.

"The standard for regulating the safety of dietary supplements is largely untested, but we are committed to finding the right public health solution,'' McClellan said.