Nearly a dozen poachers were jailed by an Indonesian court Thursday over the 2020 killing of five critically endangered Sumatran elephants and the illegal trade of their lucrative tusks, as the Southeast Asian archipelago's battle with wildlife crime continues.

Rampant deforestation has reduced the elephants' habitat and brought them into increasing conflict with humans, while their ivory tusks are prized in the illegal wildlife trade.

Authorities found the dead elephants -- killed by electrocution and with their tusks removed -- in early 2020 at a palm oil plantation in the remote village of Tuwie Peuriya in Aceh, which sits on the tip of Sumatra Island.

Aceh Jaya district court in Sumatra handed nine men jail sentences between 10 months and nearly three-and-a-half years for the poaching.

Two others were jailed for almost two years for their involvement in the trade of the elephants' tusks.

"The panel of judges considered thoroughly and in detail the different roles of each convict and attributed different sentences to them," said court spokesperson Nadia Yurisa Adila.

"These elephants are protected elephants. Therefore, the convicts are subjects to the law on natural resources and ecosystem conservation."

Aceh's Natural Resources Conservation Agency estimates the animals died two months before their discovery in January 2020 from high-voltage electrocution by a fence intentionally installed at the palm oil plantation. 

The investigation lasted more than a year and resulted in police arresting the perpetrators in August and September last year.

There have been several incidents of elephant poaching by poisoning, electrocution or decapitation on the island in recent years.

A one-year-old elephant died after losing half of its trunk in a poacher's trap in November, while in July an elephant was found beheaded and its tusks removed after being poisoned.

Aceh's conservation agency estimates the region has only about 500 Sumatran elephants still living in the wild and global conservation agencies estimate as few as 2,400 remain.

The elephant's survival status was raised from "endangered" to "critically endangered" in 2012 after half of its population was lost in just a few decades.