DHAKA, Bangladesh » A river ferry carrying about 100 passengers capsized and sank in central Bangladesh on Sunday and a rescue operation was underway, an official said.

The ferry was reportedly hit by a cargo vessel at the Daulatdia-Paturia crossing on the Padma River on Sunday afternoon, said fire department official Shahzadi Begum.

It was not immediately clear how many people survived or are missing. The site is 40 kilometers (25 miles) northwest of the capital, Dhaka.

Begum said rescue teams were deployed and many passing boats were helping in the operation.

Inspector Zihad Mia, who is overseeing the rescue, told The Associated Press by phone that the ferry was submerged at a depth of up to 20 feet (6 meters).

"We have not recovered any dead body, and we don’t have a clear picture about how many were exactly in the ferry when it sank," he said. "But I think many have survived."

He said divers would soon be deployed to determine the exact position of the ferry.

"We are trying to gather details from the survivors," he said.

The Padma is one of the largest rivers in the delta nation, which is crisscrossed by more than 130 rivers.

Overcrowding and poor safety standards are often blamed for ferry disasters in the impoverished South Asian nation.

Last August, a ferry with a capacity of 85 passengers was found to be carrying more than 200 when it capsized also on the Padma near Dhaka, leaving with more than 100 people dead or missing. The owner was arrested after weeks in hiding on charges of culpable homicide, unauthorized operation and overloading.