At least 26 workers were killed and two more injured when an under-construction railway bridge collapsed in northeastern India on Wednesday.

The state-run railway authority opened an investigation in the accident that happened in Sairang town in the northeastern state of Mizoram, Chief Minister Zoramthanga, said on social media platform X.

Media reported that up to 40 workers were at the site when the bridge collapsed but police said 28 workers were present.

"Rescue workers have been able to recover 13 bodies so far. Efforts are on to recover the remaining bodies," said a state police official who declined to be identified.

The Northeast Frontier Railway (NFR) said in a statement on X that the mishap occurred during work on the Bhairbi-Sairang New Line Railway Project.

The NRF said on its website the project will connect Mizoram to the rest of the country, boosting "tourism and socio-economic development."

A "high-level inquiry committee" had been set up to investigate the accident, the NFR said.

Prime Minister Narendra Modi said in a statement that "all possible assistance" was being given to those affected.

India's extensive railway system is used by many millions of people every day.

The government has launched high-speed trains as part of plans to modernize the network but critics say it has not focused enough on safety and upgrading aging infrastructure.

At least 288 people were killed in June in India's worst rail crash in more than two decades. It was blamed on signal failure.

In October last year, a colonial-era suspension bridge collapsed in the western state of Gujarat killing 135 people.