At least 20 people died in a train crash in southern Italy

At least 20 people died and dozens were injured when two passenger trains collided head-on in southern Italy on Tuesday, the president of the Province of Bari said, according to the Associated Press.

The crash happened on a single stretch of track in the countryside between the towns of Corato and Andria. Both trains were made up of four carriages.

Images showed carriages smashed and crumpled by the force of the impact, with debris flung out amongst olive trees which flanked both sides of the track.

"We are working with dozens of rescue teams to open up the carriages," said Luca Cari, a fire service spokesman, adding they had saved a young boy from the wreckage.

"The rescue is complicated because this happened in the middle of the countryside," he said.

Corato mayor Massimo Mazzilli shared images of the aftermath on Facebook. "It looks like an airplane crash," the mayor wrote.

There was no immediate reason given for the collision, which took place at around 11.30 am local time on a hot summer's day in the region of Puglia.

"We won't stop until we get a clear explanation over what happened," Prime Minister Matteo Renzi told reporters, cutting short a visit to Milan in northern Italy to return to Rome.

A photograph handed to reporters by the fire brigade showed just four carriages left standing upright on the rails. A fifth carriage had jumped off the tracks, while the other three units looked crushed.

Local tv channel news24.city published footage of rescuers on YouTube:

The stretch of track is operated by a regional rail company, Ferrotramviaria. It was not clear how many people had been on the trains.

The last major rail disaster in Italy was in 2009 when a freight train derailed in Viareggio, in the center of the country, with more than 30 people living close to the tracks killed in the subsequent fire.