Ten endangered Borneo pygmy elephants were found dead in a Malaysian forest, with wildlife officials suspecting that poisoning could be the cause of the deaths.

Over the last three weeks, carcasses of elephants were found near each other at the Gunung Rara Forest Reserve, in Malaysia's Sabah state on the island of Borneo. They had reportedly suffered internal bleeding.

According to a Reuters report, the first elephant died Dec. 29, with more elephants continuing to be found dead in the past three weeks. The last elephant's death took place Jan. 24.

A 3-month-old calf trying to wake its dead mother was rescued by the officials. They have been trying to find the cause of the deaths and speculate that the elephants might have been poisoned. Whether the elephants were poisoned intentionally is not known, though.

"This is a very sad day for conservation and Sabah. The death of these majestic and severely endangered Bornean elephants is a great loss to the state," Sabah Environmental Minister Masidi Manjun said in a statement. "If indeed these poor elephants were maliciously poisoned, I would personally make sure that the culprits would be brought to justice and pay for their crime."

In the last few years, some elephants have been killed by poachers for their tusks. But in this case, the tusks of the elephants remained intact and the officials did not find any gunshot injuries, suggesting that the elephants were not killed by poachers.

Post-mortem reports showed that the animals had suffered hemorrhages and ulcers in their gastrointestinal tracts, according to The Associated Press.

The pygmy elephants of Borneo are baby-faced animals that have oversized ears, plump bellies and tails. They are native to the forests of Borneo and Sumatra. According to World Wildlife Fund (WWF), currently there is a population of about 1,500 Borneo pygmy elephants. WWF has listed the species as endangered.