Summary：Emergency crews searched mangled carriages on Sunday for any further victims after a train crash in northern India killed 23 passengers, the fourth major accident this year on the crumbling network

Emergency crews searched mangled carriages on Sunday for any further victims after a train crash in northern India killed 23 passengers, the fourth major accident this year on the crumbling network.

Another 156 people were injured when 14 carriages came off the tracks in Muzaffarnagar district in Uttar Pradesh state, 130 kilometers from New Delhi, on Saturday evening.

The coaches were left in a mangled heap after the express train derailed at 100 kilometers per hour, crashing into nearby houses and a college.

Rescuers used gas-powered saws to prise apart the tangled metal and search the wreckage with sniffer dogs.

"We are checking the coaches thoroughly for any survivors or bodies. We will clear the tracks today," said Anant Dev, Muzaffarnagar district police chief.

A large crowd descended on the accident site to help free passengers from the damaged carriages, many of which were upended and torn open.

Some of the injured were seriously hurt but many had been released from hospital after receiving treatment, Dev added.

The Utkal-Kalinga express left Puri, a temple city in India's coastal east, on Thursday evening and was scheduled to arrive in the northern Hindu holy city of Haridwar on Sunday.

The government has ordered an inquiry into the accident amid speculation unscheduled maintenance work was under way at the time.

"It's too early to make any claims. Maintenance happens round the clock but everything will be clear after the probe is completed," a senior railway official said on condition of anonymity.

Another railway official, R.N. Singh, told the Press Trust of India there was "routine work" under way but would not elaborate given the pending investigation.

Criminal investigators were also probing whether sabotage was involved.

Railway Minister Suresh Prabhu said the board had been directed to "fix responsibility" by end of the day.

"Will not allow laxity in operations," Prabhu said in a post on Twitter.

India's railway network is the world's fourth largest and remains the main form of travel in the vast country, but it is poorly funded and deadly accidents often occur.

Experts blame underinvestment and poor safety standards for the frequency of rail accidents.

This latest derailment is the fourth major crash this year, and follows another accident in Uttar Pradesh last November that left 146 dead.

In January nearly 40 people were killed when a passenger train derailed in the southern state of Andra Pradesh.

A 2012 government report described the loss of 15,000 passengers to rail accidents every year in India as a "massacre".

But the network continues to struggle due to a severe funding shortfall. In 2015, Prime Minister Narendra Modi's government pledged to invest $137 billion in the system over the next five years.

"Over the next five years, the railways have to undergo a transformation. We have to make Indian Railways a benchmark organization in safety, security and infrastructure," Prabhu said at the time.

"But no improvement is showing on ground. It's time to act fast to revive the ailing railways," said Sukumar Chaubey, a rail safety expert.