India's health ministry has ordered government agencies to enforce a new rule for bigger health warnings on cigarette packs, stepping up a fight against the country's $10 billion cigarette industry that has shut down its factories in protest.

The health ministry's action highlights a growing conflict between the tobacco industry and the federal government which wants manufacturers to cover 85 percent of a cigarette pack's surface in health warnings, up from 20 percent.

India's biggest cigarette maker ITC Ltd, part-owned by British American Tobacco, has not implemented the government order, saying it contradicts a parliamentary committee's recommendation for warnings to cover half a cigarette pack.

K.C. Samria, a joint secretary in the health ministry, wrote to government departments on Monday to ensure strict implementation of the new rules, letters seen by Reuters showed.

"The implementation of the rules requires strong support," Samria said, adding bigger warnings would create awareness about the ill effects of tobacco use.

Smoking kills about 1 million people in India each year, according to researchers at BMJ Global Health.

The rules will also apply to imported cigarette packets, as well as those being sold at duty-free shops at Indian airports.

"DRASTIC" RULES

The tobacco industry has said the new rules are impractical and create ambiguity as the parliamentary panel's report had called for warnings to cover half the packs' surface area.

The panel's report is not binding on the government.

ITC and its rival Godfrey Phillips India Ltd, which is a partner of U.S.-based Philip Morris International, shut factories on Friday in protest.

The Tobacco Institute of India estimated the production halt costs the industry $53 million a day.

ITC has said it is currently not ready to print bigger warnings on its packs. Godfrey has said it has started preparatory work to print new warnings.

ITC said it did not have any immediate comment on Tuesday. Godfrey could not immediately be reached for a comment.

A health ministry official said the directives on health warnings were clear and it would not bow down to the industry's "pressure tactic" of shutting the factories.

"The ministry has handled industry pressure well, it is a commendable step," said Amit Yadav, director, southeast Asia region at Framework Convention Alliance for Tobacco Control, a group of more than 350 organizations.

(Reporting by Aditya Kalra; Editing by Sanjeev Miglani and Jane Merriman)