At least 13 school children were killed and 12 injured after a train rammed into their van at an unmanned railway crossing in Uttar Pradesh's Kushinagar on Thursday, an official said.

According to a railway official the incident occurred around 7.10 a.m., at the Behpurva railway crossing, around 100 km from Gorakhpur.

Railways spokesperson Ved Prakash told that the children of the Divine Public School died on spot when the Siwan Gorakhpur passenger train crashed into the van at the crossing.

According to a North Eastern (NE) Railway official, at least 25 people, mostly children below the age of 10 years were travelling in the van when the incident occurred.

The train was on its way to Gorakhpur from Siwan.

An accident relief medical train from Gorakhpur has been dispatched to the site, the NE official said.

He also said that the several senior officials have rushed to the accident site. An inquiry has been ordered.

According to Railway Ministry, it was an unmanned level crossing gate with Gate Mitra deployed there.

Injured children have been rushed to Pandrauna Hospital which is 30 km from the accident site.

Railway Minister Piyush Goyal expressed his grief over the accident and announced an ex-gratia of Rs two lakh each to the kin of the victims.

"I am saddened by the news of school children dying in a train accident. I have spoken to senior railway officials and ordered an inquiry into it," Goyal said in a tweet.