New Delhi, Aug. 25 -- Indonesia intensified its ground and aerial firefighting operations Monday as huge blazes in central and western regions scorched wide areas of forests and peatland, creating a choking haze that blanketed cities and crossed borders.

Indonesian police have arrested 72 people suspected of starting some of the forest and peatland fires, while four companies are under investigation for allegedly using fire to clear land at low cost.

Emergency services have been battling fires driven by an intensifying El Nino pattern and a prolonged dry season, generating dense smoke that crossed into Malaysia and Brunei, according to the National Disaster Management Agency, or BNPB.

Fires remained active in several regions on Monday,...