Kollam (Kerala) | The side retaining wall of an under-construction flyover on the NH-66 stretch collapsed at Mylakkadu near Kottiyam here on Friday, trapping several vehicles, including a school bus on the service road, police said.

The incident occurred around 4 pm at the under-construction Kadampattukonam-Kollam section of National Highways in Kottiyam.

The retaining wall of the flyover caved in, damaging the service road below, they said.

A few vehicles, including a school bus, were caught on the damaged service road a short distance from where the wall collapsed, police added.

Police said that people in these vehicles, including students on the school bus, were rescued and taken to safer places.

Officials of the National Highways Authority of India (NHAI) said they were assessing the situation.

Kollam District Collector N Devidas and senior police officers visited the place to evaluate the situation.

Police officials said that traffic diversion will remain in place until the rectification work is completed.

Public Works Minister P A Muhammad Riyas, in a statement, said that the PWD Secretary has been directed to conduct an inquiry and submit a report.

As the project is being executed by the NHAI, the matter will be taken up with it, he said.

Congress MP K C Venugopal alleged that poor quality construction due to corruption has resulted in repeated collapses involving under construction roads.

"This construction is inviting disaster," he alleged.

"People are struggling to get a proper road. The government has a responsibility to ensure safety."

He said the state government was more focused on finishing NH projects before the Assembly election, due next year.

"They want to inaugurate the road, but at least they should ensure it is safe for the public,"he added.