Doctors warned the public Friday to stay away from alternative forms of tobacco.

Bidis, a tobacco product that originated in India, are tobacco wrapped in India-native tendu plant leaves. They're often flavored and contain three times the tar, carbon monoxide and nicotine of regular cigarettes.

Clove cigarettes are imported from Indonesia and sold with or without filters. They have twice the tar and nicotine as regular cigarettes.

Hookahs, a communal pipe usually containing a flavored tobacco, produce smoke that contains carbon monoxide, heavy metals, nicotine and carcinogens, a report on the Mayo Clinic Web site said.

The World Health Organization warned that a 45-minute hookah session was equivalent to smoking 100 cigarettes at once.