Taiwanese authorities on Sunday banned smoking in all indoor public places in what campaigners say is a "milestone" in turning Taiwan into a smoke-free island.

Smoking had previously been banned in public areas including hospitals, schools, theatres, libraries, office buildings and elevators.

Under the new law, it is banned in all other public facilities such as hotels, restaurants, karaoke bars, Internet cafes and roofed transport stations.

Those caught lighting up in smoke-free facilities will face fines of up to 10,000 Taiwan dollars (300 US dollars).

"The new law is a milestone in making Taiwan a smoke-free country," said Lin Ching-li, spokeswoman for the non-profit John Tung Foundation, one of the lobbying groups behind the campaign.

Airports have closed their smoking rooms and local air carriers are barred from voluntarily selling cigarettes to passengers during flights under the new law.

Health authorities estimate that half a million establishments could be affected by the new law, which became effective after its 18-month grace period expired. The amended law passed the legislature in June 2007.

On Sunday, the Taipei city government said its inspectors had found five out of 2,740 public facilities failed to post anti-smoking signs at the entrance, leaving them subject to fines of up to 50,000 Taiwan dollars.

The new law also doubled the "health tax" to 500 Taiwan dollars for every 1,000 cigarettes and each kilogram of tobacco and cigars to raise money for the island's cash-strapped national health insurance