A child was killed in a strong 6.4-magnitude quake that hit the southern Philippines on Wednesday, a local mayor said, as houses collapsed, power was knocked out and a shopping mall burst into flames.

Residents evacuated homes and buildings across the Mindanao region including a mall that caught fire in the city of General Santos shortly after the quake struck in the evening, officials said.

The child died in a house collapse in the town of Datu Paglas, while four residents of nearby Tulunan town were injured when at least two other houses fell down, Tulunan Mayor Reuel Limbungan told AFP.

"The child was crushed by a collapsed house wall" and pronounced dead in hospital, Limbungan said, adding that he had visited the medical facility and spoken to its director.

Rescue and local officials said there were no immediate reports of deaths elsewhere in Mindanao, and rescue official Anthony Allada told local television that 20 people were treated for injuries in the town of Magsaysay, near the epicentre.

Three other people were hurt in the town of M'lang, added its vice-mayor, Joselito Pinol.

The quake was 14 kilometres (8.7 miles) deep and was followed by at least two aftershocks, according to the United States Geological Survey (USGS).

"It was the most powerful earthquake I have ever experienced," Sara Duterte, mayor of the largest Mindanao city of Davao, and daughter of President Rodrigo Duterte, told local television.

The Philippines is part of the Pacific "Ring of Fire", an arc of intense seismic activity that stretches from Japan through Southeast Asia and across the Pacific basin.

An elderly man was treated for injuries after being struck by a falling object during the evacuation of a Davao mall, local TV reported.

Jerome Barranco, civil defence officer for the region, said several people were also injured in the city of Kidapawan "as a result of falling debris".

In General Santos, television footage showed firemen battling a blaze that engulfed the three-storey Gaisano shopping mall.

It was not known if there were still people inside the building, which was evacuated as the quake struck. The blaze was still raging more than three hours later despite the efforts of nearly 100 firemen, fire officer Redentor Batulan told AFP.

Copyright Agence France-Presse, 2019