The accident happened in the town of Khatauli whilst the Kalinga-Utkal Express was travelling from the eastern city of Puri to Haridwar city in the north of the country.
The local administration is carrying out rescue operations and a team from the National Disaster Response Force (NDRF) have been at the scene.
Railways spokesman Anil Saxena said he could not confirm the number of casualties but said at least five carriages derailed.
Television footage showed several mangled carriages piled up on each other while people looked for wounded in a crowd of people as night fell.
"We have mobilized all our resources to provide the best relief and rescue operations at this time," Saxena told TV channels.
A police official earlier said 20 people had been injured but did not mention any people killed.
"There are certainly casualties but right now the focus is on evacuation," senior police officer Jitender Kumar told AFP by phone from the accident site.
"We are shifting everyone to the hospital. We are trying to take out those trapped inside the coaches."
Photographs from the scene showed people climbing onto upended carriages to try to pull passengers out.
The accident is the latest disaster to hit India's most populous state and comes just a week after dozens of children died at a hospital that had run out of oxygen.
India's state railways, built during British colonial rule, have an appalling safety record after decades of low investment and have prioritized keeping fares low for the 23 million passengers who use the network every day.
Less than a year ago 146 people died in a similar disaster in Uttar Pradesh.
A 2012 government report said almost 15,000 people were killed every year on India's railways and described the loss of life as an annual "massacre".
India recorded 27,581 railway deaths in 2014, the most recent year for which figures are available, with most victims falling from, or being struck by, moving trains.
Prime Minister Narendra Modi's government has pledged to invest $137 billion over five years to modernize the crumbling railways, making them safer, faster and more efficient.