Heavy rain that has drenched eastern Bolivia's Chiquitania tropical savanna has put out fires that have ravaged millions of hectares in recent months, authorities said Sunday.

A firefighter attempts to extinguish a fire on a boat off the coast of Santa Cruz Island, California on Monday. Rescuers were scrambling to reach more than 30 people who were sleeping below deck when their scuba-diving boat caught fire with reports of "numerous fatalities" as of press time. A major rescue operation was underway for the dozens of people trapped aboard the 75-foot (22-meter) boat. Photo: AFP

"It has rained all across Chiquitania. And our satellite no longer shows any active forest fire," said Cynthia Asin, the top sustainable development official in the Santa Cruz region.

Still, she said, firefighters will wait 24 hours to be sure that all fires are completely out before they head out of the area.

The eastern department of Santa Cruz has been the hardest hit of Bolivia's nine departments since the fires began in May and intensified in late August

Bolivia in August enlisted special firefighting planes, a Supertanker Boeing 747 and a Russian Ilyushin, as well as helicopters, 5,000 firefighters, soldiers and police to combat the blazes.

The fires, which have devastated more than four million hectares since August, completely destroyed the primary forest extending over 100 hectares in the Tucavaca reserve in Santa Cruz.

There were no immediate reports on whether fires in other parts of the country, including Tarija in the south and Cochabamba in the center, were extinguished.

Environmentalists blame laws enacted under leftist President Evo Morales, who has encouraged burning of forest and pasture land to expand agricultural production. 

The government attributes the blazes to dry weather and flame-fanning winds.