A Lockheed L100-30 Hercules aircraft of the Australian government is seen at Sultan Mahmud Badaruddin II International Airport in Palembang, Indonesia, during preparations before being deployed to extinguish forest fires, Oct. 14, 2015. Reuters/Antara

Russia is sending two amphibious water-bombing planes to help Indonesia fight forest fires that have spread a "haze" over neighboring countries.

The Beriev Be-200s were scheduled to arrive Wednesday in Palembang, a city on Sumatra island, the Jakarta Post reported, citing the National Disaster Mitigation Agency. The planes can scoop 12,000 liters of water from rivers, lakes or the sea and dump it over the fires.

Russia is taking over from Malaysia and Australia, which have ended their five-day missions, the Post said. Ten Indonesian aircraft and one from Singapore continue to conduct water-bombing and rain-inducing operations.

Malaysia and Singapore have had to cancel classes, sporting events and other activities because of the haze, which occurs every year as palm oil growers and paper manufacturers use fire to clear forests to plant more trees. It's blamed for respiratory illnesses and for harming tourism in beach resorts like Phuket. It's now reached the southern Philippines, the Rappler news website reported, citing that country's weather agency.

This year's haze could be among the worst, Time and other media have reported a NASA scientist as saying. Indonesian President Joko Widodo has said it could take three years before efforts to curtail the forest burning have an impact. After earlier refusing help, he asked Malaysia, South Korea, China, Australia, Japan and Russia this month for assistance.