Official says 37 people are injured, as Spain observes three days of mourning for the 42 killed in an earlier train collision.

One person has been killed and dozens injured after a Spanish commuter train crashed into the rubble of a wall that collapsed onto railway tracks outside Barcelona, emergency workers said.

The crash in the municipality of Gelida, approximately 40km (25 miles) west of Barcelona, in Catalonia in northeastern Spain on Tuesday, comes just two days after a separate train collision killed at least 42 people in the country’s southern Andalusia region.

Claudi Gallardo, inspector for the fire service in the Catalonia region, said in televised comments from the site of Tuesday’s crash that 37 people had been injured, four of them seriously, and the train driver had died.

“There are four seriously injured, and one person who has passed away,” Gallardo said, adding that all passengers had been removed from the site of the crash.

Catalonia’s civil protection agency posted on social media that “a retaining wall collapsed onto the tracks, causing an accident involving a passenger train”.

Spain’s railway operator ADIF said the wall likely collapsed due to heavy rains that swept across the region this week.

The latest crash comes as Spain began three days of mourning for the victims of Sunday’s deadly train accident that took place some 800km (497 miles) away, near Adamuz, Cordoba province, in Andalusia.

Sunday’s crash happened at 7:45pm local time when the tail end of a train carrying 289 passengers on the route from Malaga to the Spanish capital, Madrid, derailed and crashed into an incoming train, travelling from Madrid to Huelva, another southern city, according to ADIF.

The front of the second train, which was carrying 184 people, took the brunt of the impact, which knocked its first two carriages off the track and down a 4- metre (13-foot) slope.

Some bodies were found hundreds of metres from the crash site, according to Andalusia’s regional president, Juanma Moreno.

Spanish Minister for Transport Oscar Puente called the devastating crash “truly strange”, since it occurred on a straight line, and neither train was speeding.

Puente said officials had found a broken section of track that could possibly be related to the accident’s origin, while insisting this is just a hypothesis and that it could take weeks to reach any conclusions.

“Now we have to determine if that is a cause or a consequence [of the derailment],” Puente told Spanish radio Cadena Ser.

At this time, “all hypotheses are open”, he said.

Al Jazeera’s Natacha Butler, reporting from Cordoba in southern Spain, said the latest crash will “put a lot of pressure” on the Spanish government and rail authorities “to try and reassure people that they can catch a train in Spain and it’s going to be safe”.