Forest fires in Indonesia, which have cloaked Singapore in record-breaking smog, are raging on palm oil plantations owned by Indonesian, Malaysian and Singaporean companies, environmental group Greenpeace said Saturday.
Singapore's worst environmental crisis in more than a decade has seen the acrid smoke creep into people's flats and shroud residential blocks as well as downtown skyscrapers, and the island's prime minister has warned it could last weeks.
"NASA hotspot data in (Indonesia's) Sumatra over the past 10 days (11-21 June) has revealed hundreds of fire hotspots in palm oil concessions that are owned by Indonesian, Malaysian and Singaporean companies," the group said in a statement.
Singapore's smog index hit the critical 400 level on Friday, making it potentially life-threatening to the ill and elderly, a government monitoring site said. On Saturday morning, the reading was at 323, still in the "hazardous" zone.
Parts of Malaysia close to Singapore have also been severely affected by the smog this week.
"Fires across Sumatra are wreaking havoc for millions of people in the region and destroying the climate. Palm oil producers must immediately deploy fire crews to extinguish these fires. But really cleaning up their act starts with adopting a zero deforestation policy," said Bustar Maitar, head of Greenpeace Indonesia's forest campaign.
Indonesia is the world's top producer of palm oil, which is used for many everyday items such as soap and biscuits.
The country's carbon-rich rainforests and peatlands have for decades been wiped out to extract the timber as well as to clear the land for palm oil plantations and mining activities.
Indonesia last week sought to shift some of the blame for the raging forest fires on Malaysian and Singaporean palm oil companies that had invested in Indonesia.
Indonesia's Environment Minister Balthasar Kambuaya said Friday that eight companies suspected to be behind the fires were under investigation, promising to reveal their names after the probe.
A senior presidential aide Kuntoro Mangkusubroto said Friday that the fires happened in concession areas belonging to two paper producers—Asia Pulp & Paper (APP) and Asia Pacific Resources International (APRIL).
"It is very clear that the fires are in APP concessions and APRIL. We need to settle this matter," he told reporters.
APP, the world's third-largest paper producer said in a statement late Friday that "ground verification" detected "only seven points that are actually forest fire, affecting around 200 hectares of land".
"They are under and being controlled by approximately a thousand fire fighting crews and their team. Our team's preliminary investigation found that five of the fires were set by the community to clear land for crops and two cases are still under investigation," APP added.
APRIL denied the government findings, calling for a thorough investigation.
"APRIL has maintained a strict no-burn policy in its concessions since commencing operations in 1994," a company statement said.
"While there have been small number of fires within their concessions over the past three weeks, all of those fires were spread from fires that began outside our concession," it added.
Indonesia stepped up its fire-fighting efforts Friday by deploying aircraft to artificially create rain and to water bomb the blaze.
The haze crisis has caused a dramatic escalation in tensions between tiny Singapore and its vast neighbour, with the city-state repeatedly demanding that Jakarta steps up its efforts to put out the fires.
Explore further: Seafood supply altered by climate change