PNG volcano forces Qantas flight changes

An ash cloud from a volcano in Papua New Guinea has prompted minor alterations to Qantas flights between Sydney and Narita and Sydney and Shanghai.

Flights QF21, QF22 and QF130 will fly over central PNG to avoid the cloud over Rabaul.

"The new flight paths won't really impact the flight time," a Qantas spokesperson told AAP.

"It will be five minutes if anything."

The Mount Tavurvur volcano has erupted in eastern PNG, spewing rocks and ash into the air and forcing the evacuation of local communities.

The volcano, which destroyed the town of Rabaul when it erupted simultaneously with nearby Mount Vulcan in 1994, rumbled to life early on Friday morning on the tip of the island of New Britain.