(CNN) -- Kenyan park rangers are hunting for a gang of poachers who they say killed eleven elephants and hacked off their tusks, the latest large slaughter of the animals to be reported amid insatiable global demand for ivory.
The family of elephants were killed on Saturday in Tsavo East National Park in southern Kenya, according to a statement Monday from the Kenya Wildlife Service. The animals' carcasses all had bullet wounds and their tusks had been chopped off, the agency said.
Teams of rangers on foot and in the air are trying to track down the poachers in the 22,000-square-kilometer (8,500-square-mile) park, the country's largest single ecosystem, according to the wildlife service. It said it believed around 10 poachers were involved.
The killing follows warnings last year from conservation groups that elephants were being slaughtered in Africa at an alarming rate to feed demand for ivory from increasingly affluent Asian countries, particularly China and Thailand.
At the same time, the groups said, poachers are becoming more heavily armed, making it harder for often ill-equipped park wardens to protect the animals.
In an indication of the amount of illegal ivory in circulation, authorities in the Asian port of Hong Kong have announced three major seizures of smuggled shipments since October.
They confiscated 779 pieces of tusk, worth the equivalent of about $1.4 million, last week.
The Tsavo park, a protected area, is home to an estimated 13,000 elephants, based on a census in 2011, Kenya Wildlife Service said.
A representative of the agency wasn't immediately available to comment Tuesday on the latest developments in the pursuit of the poachers.
CNN's David McKenzie reported from Johannesburg, South Africa, and Jethro Mullen reported and wrote from Hong Kong.