Sumatran tigers are on the brink of extinction because of the destruction of forests, poaching and clashes with humans.

Their numbers have dwindled to about 400 from 1,000 in the 1970s, according to the World Wildlife Fund, which set up the cameras in Riau and Jambi provinces just three months ago.

Karmila Parakkasi, who heads the group's tiger research team on Sumatra island, said capturing a dozen cats in such a short period is astonishing.