Maniktala: A stretch of Vivekananda Road near Maniktala has been closed to traffic after a portion of the road caved in on Sunday and the Calcutta Municipal Corporation dug a pit to detect and repair the cause.

Buses, cars and autorickshaws headed towards Girish Park from Maniktala are being diverted through Amherst Street from Maniktala Chaltabagan since Sunday morning. But there is no bar on vehicles headed towards Maniktala along Vivekananda Road.

Traffic slowed down to a snarl on Monday. Police have put up a temporary signage requesting motorists to take other roads.

"It is better if people coming towards Girish Park take other roads from the Maniktala crossing. It will help them reach their destinations faster," said a police officer.

It would take at least three more days for the cave-in to be repaired and the road restored for traffic, a civic official said.

A resident of Maniktala said vehicles moved at a snail's pace from Kankurgachhi rail bridge as there was a long queue of vehicles ahead on Monday.

A depression was first noticed on the Girish Park-bound flank of Vivekananda Road, near the crossing of Vivekananda Road and Amherst Street, on Sunday morning. "We cordoned off the caved-in portion and alerted engineers of the Calcutta Municipal Corporation," a police officer said.

The corporation started digging the road on Sunday afternoon. A pit about 10ft deep, 6ft long and 3ft wide pit had to be dug to find the cause of the depression. "There is a brick sewer line about 10ft below the surface. So we had to dig that deep to check if any leak in the brick sewer had led to the cave-in," a CMC engineer said.

The engineers found that a sewer line that connects some houses with the brick sewer had leaked. The water leaking from the line had triggered the cave-in. "The drainage department will first repair the leak and only then can restoration work begin. It is difficult to say how many days it will take," said the engineer.