Two Sumatran tigers at an Indonesian zoo are recovering from Covid-19 after testing positive in mid-July, the Jakarta government has said in a statement, adding that authorities are trying to find out how they were infected.

Tino, a 9-year old tiger, and Hari, a 12-year old, were tested for coronavirus after both showed flu-like symptoms, had trouble breathing and lost their appetite, the statement says, according to Reuters.

The tigers had undergone around 10 to 12 days of treatment and were gradually showing signs of recovery, Jakarta's Head of the Parks and City Forest Office, Suzi Marsitawati, said.

"Their appetites have returned and they are back to being active," Suzi said, although both tigers remain under close observation. She said authorities are doing tracking and tracing to figure out how the tigers were infected.