Jakarta – Haze from forest fires that is fouling skies over Indonesia and Malaysia may worsen in coming months as farmers continue to torch land to make way for crops, the government was quoted as saying on Monday.

Bush fires have sent smoke billowing over large parts of Indonesia's Sumatra and Kalimantan islands in recent months. The haze has also spread to neighbouring Malaysia.

Air quality in both countries has dropped, and flights have been delayed in Indonesia. Malaysian officials have warned that the problem – which has occurred sporadically since 1997 – is hurting regional tourism.

'The condition could worsen because people keep on burning the forests for farming,' The Jakarta Post quoted Mr Sudariyono, deputy minister for ecosystem maintenance, as saying. 'In addition, there is no indication that rainfall will start soon.' He said the central government could do little to stop the haze apart from instructing regional administrators to crack down on the problem.

In 1997-98, wildfires in Sumatra and Kalimantan provinces burned out of control for weeks, ravaging 10 million hectares of scrub land and blanketing nearby Singapore and parts of Malaysia and Indonesia with thick smoke.

Economic losses from those fires topped US$9.3 billion and prompted a 2002 agreement among six of the 10 Asean members to fight fire pollution. Indonesia has yet to ratify the deal.