Indonesian Pres. B.J. Habibie yesterday ordered immediate action to stop forest fires burning in the areas of Sumatra and Kalimantan, which are causing a thick, choking haze throughout much of Southeast Asia. But Walhi, Indonesia’s leading environmental group, said the government is much too late in moving to tackle the fires, which are being set by plantations and small farmers to clear land. Over the weekend, an oil tanker and a tugboat collided in the haze, killing 10 crew members and causing an oil spill that caught fire and engulfed a nearby cargo ship.