A deadly train crash in Iran has claimed the lives of at least 15 people, and injured more than 50 others.

Two passenger trains collided in Semnan province early on Friday morning. In total four carriages derailed, and two caught fire. No reason has yet been advanced as to why one train crashed into the other, which was immobile at a station platform at the time.

#İran‘ın #Semnan kentinde İki tren çarpıştı; en az 16 ölü ve yaralı var. pic.twitter.com/AZIP5hRiKK— Mecid İsmailzade (@m_ismailzade) 25 novembre 2016

Officials at Haft-Khan station in the city of Shahroud, about 400 kilometres east of the capital, Tehran, have launched an investigation into the accident.

#BREAKING: At least 8 killed, 15 injured after 2 passenger trains collided in #Iran’s #Semnan province on Friday, local media reports pic.twitter.com/G4tswrA38X— People’s Daily,China (@PDChina) 25 novembre 2016

The main line between Tehran and Iran’s second city Mashhad is running a restricted service, and aid will take time to reach the accident site as it is in a remote area, for the moment accessible only by Red Crescent helicopter, reported state TV.

#Iran’s Red Crescent Society officially inducted all 6 Bell 412EPs recently procured from #US into its service during a ceremony today. pic.twitter.com/pYOOJD5XHH— Babak Taghvaee (@BabakTaghvaee) October 8, 2016