Hundreds have been killed and towns devastated by a spate of deadly earthquakes in countries including Mexico, New Zealand, Japan and Vanuatu.

While experts are unable to pin down the reason why 2017 has seen an unusual amount of earthquake action, a seismologist has suggested it could be due to travelling "body waves".

The theory is that the waves caused by one earthquake can shake up the fault line in other countries across the globe and cause a second event.

Rescuers worked throughout the night in search of survivors in Mexico. Source: AP

"Waves that travel throughout the globe might shake up faults and bring faults already stressed closer to failure," Senior Seismologist Phil Cummins from Geoscience Australia told 7 News Online.

"It's very difficult to determine."

Professor Cummins said alternatively, the earthquakes could just be part of a random clustering.

Mexico has been struck by two earthquakes in just 12 days, killing more than 230 people and bringing buildings to the ground.

Volunteers bring pieces of wood to help prop up sections of the collapsed school.

The quake that hit the southern part of the country September 7 on had a magnitude 8.1 and Tuesday's event was measured at 7.1.

Vanuatu was also hit with a 6.1 magnitude earthquake on Thursday and a 5.7 magnitude quake struck off the coast of Bali hours later.

Professor Cummins said these earthquakes are relatively small in magnitude, but smaller quakes can cause more damage, depending on the fault line.

In Mexico, a desperate search and rescue effort is continuing.

At least 21 children have been killed after a three-storey wing of the Enrique Rebsamen school in Mexico City collapsed during the 7.1 magnitude earthquake that struck Tuesday.

Search crews are frequently pausing for “moments of absolute silence” as they listen for trapped survivors’ cries and banging on walls.