At least 22 people have been killed and dozens more injured in a stampede on a bridge near a railway station in India's financial hub of Mumbai.

The incident on Friday occurred during morning rush hour amid a heavy downpour on a footbridge in Mumbai's Elphinstone station, which connects two of the city's major local lines.

TV footage showed injured people lying on the ground and locals attempting to revive them by administering chest compressions. Officials said the death toll was likely to rise.

"There was chaos all around on the narrow bridge, people jumped over each other, and many were seriously injured," police officer Sunil Deshmukh said.

Railways spokesman Ravinder Bhakar said a number of people had taken shelter near the train station to escape the heavy rain.

"A stampede-like situation developed. More than 30 people are injured," he told dpa news agency.

Anguished by the loss of lives in the stampede in Mumbai. Condolences to the bereaved families; prayers with injured — #PresidentKovind — President of India (@rashtrapatibhvn) September 29, 2017

The stampede was triggered by falling concrete that hit the bridge railing, causing people in the crowd to surge forward to escape as they thought the bridge was collapsing, Mumbai police official Gansham Patel said.

Avinash Supe, dean of KEM Hospital, told AFP news agency there were 22 dead.

"There was a huge crowd on the FOB [foot overbridge]. Everybody tried to leave at once, and it appeared one of them slipped and fell, triggering the stampede," Indian Railways spokesman Anil Saxena told reporters.

Tanaji Pawar, a spokesman for Mumbai's disaster management office, warned the death toll "is likely to go up".

"We put everybody who was injured in cars, police vans, and ambulances and tried to take them to the hospital as quickly as possible," one witness said. "There were three-four women who were badly injured. I don't know whether they survived."

Official figures say some 3,400 people died in 2016 either from falling off trains or while crossing the tracks of what is the world's most overcrowded suburban rail network.