These elephants are part of the herd that saw more than 30 members slaughtered.
The government of Chad said it was searching for poachers who slaughtered part of an elephant herd, while a conservation group said it had found an orphaned infant near the slaughter site.
SOS Elephants, which is based in the Central African nation of Chad, said it had counted more than 30 carcasses in the slaughter on Tuesday.
Poachers on horseback fired on the herd, which was across the river from an educational site run by the nonprofit.
The group said on its Facebook page that since the slaughter happened deep inside Chad it was probably the work of a local poaching gang, not armed groups from neighboring countries.
Photos posted on the page showed elephants with their trunks cut off, indicating the poachers were after the tusks. The illegal ivory trade is booming across Africa due to demand from Asia for ivory trinkets.
SOS Elephants founder Stephanie Vergniault noted that the slaughter was near an oil refinery run by a Chinese company, CNPC. In the past, she posted, "several of their employees" have been caught at the Chad airport "with ivory in their luggage."
One of the slaughtered elephants, with its trunk hacked off.
Vergniault on Saturday told NBC News she had contacted the security chief at the airport and he promised to get "his people to double check all luggage, mainly the luggage belonging to the Chinese."
On the Facebook page, Vergniault added it was "very likely" the orphaned infant's mother was among the elephants killed. "Very sad, very hard moments," she wrote.
Vergniault urged Chad to create a special law enforcement unit to protect its elephants, and stiffen prison time for poaching. "The poachers need to go 20 years to jail, not 2 years!" she posted.
A wildlife activist who has followed the work of SOS Elephants said getting milk supplies for the orphaned elephant will be critical.
This orphaned elephant, nicknamed Savi, did not survive after her mother was slaughtered in an earlier poaching incident. SOS Elephants founder Stephanie Vergniault is with her.
"It's difficult to raise elephants, and one problem is getting the right milk formula -- which is very expensive and is shipped from Europe," Laurel Neme told NBC News.
Nicknamed Toto, the 3-week-old male will possibly be shipped to a large elephant shelter in Kenya, said Neme, who tracks wildlife issues on her website.
"Hopefully what will happen," said Neme, who noted Toto stands a better chance than another recent orphan, nicknamed Savi, that died.
Chad's elephant population is estimated at around 3,000 — a sharp drop since the 1980s, when it had around 20,000, according to SOS Elephants.
"Tomorrow will be simply too late," Prince William warns as Africa's magnificent wild animals are mercilessly and illegally poached at a rate not seen for decades.
The slaughter occurred as nations that are part of a wildlife treaty met to work out issues such as the illegal ivory trade.
As those talks wrapped up Friday, a motion by some African nations to allow the legal sale of ivory from elephants not killed by poachers was tabled for a later meeting.
Conservation groups urged signatories of the Convention on International Trade in Endangered Species (CITES) to oppose the move, and to get tougher on the illegal wildlife trade.
TRAFFIC, a wildlife trade monitoring network funded by the World Wildlife Fund (WWF), said elephant and rhino poaching are at record levels and that countries where poaching is rampant should be barred from the international trade in wildlife.
"We should not be shy about using CITES trade suspensions as an international tool to prevent a full-blown elephant crisis," said TRAFFIC's Tom Milliken said in a statement issued by the WWF on Friday.
Just days after Rock Center aired Harry Smith's report, "The Last Stand," on the growing epidemic of illegal rhino poaching in South Africa, three of the rhinos featured in the report were attacked by poachers. Rock Center's Harry Smith reports.
On Monday, WWF said in a report that "the illegal killing of elephants in Africa is at the highest levels ever recorded, and the epicenter for poaching is Central Africa where elephant populations are experiencing localized extinctions."
Central African governments this week announced a plan to protect their wildlife, but its effectiveness is a question mark.
"It is critical that the plan is rapidly implemented because time is running out for the elephants of this region," Colman O Criodain, WWF’s wildlife trade specialist, said in the statement.
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