Malaysian plantation firms which indulge in open burning in Indonesia must be dealt with severely, visiting deputy prime minister Najib Razak said.

"We must take action against anyone who flouts the law. We do not want Malaysian companies to be involved in open burning and illegal logging. We will tag them as rogue companies," Najib was quoted as saying by the Kompas newspaper.

"We must take tough action against such firms," he added.

In October, various parts of Malaysia, including the capital Kuala Lumpur, suffered "unhealthy" levels of haze because of smoke from land-clearing fires in Indonesia.

Tourism officials warned the haze could cause the travel industry to suffer if it continued.

Malaysia expects to post a sharp rise in tourist arrivals and earnings next year in conjunction with the Visit Malaysia 2007 programme.

Tourism is Malaysia's second-largest foreign exchange earner. Officials are targeting 20.1 million visitors for 2007 generating revenue of RM44.5 billion ringgit.

A regional haze crisis in 1997 affected millions of people in Southeast Asia and did major damage to the tourism industry.

Indonesian farmers burn forests annually to clear land for agriculture, causing a haze that spreads across Southeast Asia during the dry season, increasing health problems.

The Malaysian and the Indonesian governments have outlawed land clearing by fire but weak enforcement means the ban is largely ignored.