JAKARTA (AFP) -- Hundreds of forest fires are raging across Indonesia, from the island of Borneo to Maluku, eastern Indonesia, during the country's "fire season".

Nearly 1,800 hotspots have been detected said Johnie Hadi Prakoso, according to an official from the Forestry Ministry in Jakarta. "It's very dry and there is no rain, so the farmers in the fields, sometimes illegal farmers and sometimes companies start fires," he said Saturday. "Every year from June to August is fire season."

Prakoso said that 90 percent of hotspots - areas with high ground temperatures detected by a heat sensitive satellite - are forest fires.

Earlier this week Friends of the Earth Indonesia accused 178 companies of starting fires in Indonesian Borneo and the island of Sumatra.

On Friday Indonesian police chief General Sutanto ordered all regional police heads to investigate the allegations.

Burning in Indonesia and some parts of Malaysia to clear land for crops causes an annual haze that smothers parts of Malaysia, Singapore and Thailand as well as Indonesia itself.

Indonesia's neighbours have urged Jakarta to prevent the annual forest clearing burn-offs, warning that it is hurting business and putting off tourists.

The Indonesian government has outlawed land clearing by fire but weak enforcement means the ban is largely ignored.