Table tennis chiefs say they are preparing at "full steam" for the world team championships in Chengdu later this month even after the Chinese city extended a lockdown to stamp out Covid.

The sport's governing body the ITTF is hailing the tournament as the first international sports event in China since the Beijing Winter Olympics and Paralympics in February and March.

Like the Games, the team championships will be held in a "closed-loop" bubble to thwart infections, all part of China's strict zero-Covid strategy.

Just over 1,000 people, among them about 300 players, will be in the "closed loop" for the duration of the championships, which start on September 30 and end on October 9.

Chengdu, a southwestern city of 21 million, has been effectively under lockdown for a week since reporting several hundred Covid cases, with businesses grinding to a halt and most people confined to their homes.

Measures were expected to be lifted on Wednesday, but the city government said in a notice that "the entire city will continue to deeply push forward our assault for zero-community spread".

Chengdu was also rattled by a deadly earthquake earlier this week.

Petra Sorling, president of the International Table Tennis Federation, said in a statement to AFP that "preparations are in full steam".

"We are very confident in our plans and the closed-loop management system, which was successfully implemented during the Beijing 2022 Games," Sorling said.

"With less than a month to go, we are working closely with the Chinese Table Tennis Association, the local organising committee and the authorities of the city of Chengdu to deliver a great event where all participants arrive smoothly, participate securely, and return safely."