The bodies of two oarsmen were recovered on Saturday.
Caught in strong currents, the palliyodam capsized during the ceremony before leaving for Aranmula.
A video which surfaced on the internet shows one of Kerala police team's oarsmen pushing another team's oarsman guiding that boat's stern into the stream.
All traffic has been banned from 7 am to 7 pm along the roads from District Court North Junction eastwards to Thathampally Kayal Kurissady Junction.
Competitions in country-boat races will be held at Punnamada Lake on August 29.
This year’s boat race will take place on September 4 at Punnamada Lake in Alappuzha district of Kerala.
The inaugural leg of the snake-boat races will be held at Punnamada Lake in Alappuzha alongside the iconic Nehru Trophy Boat Race on September 4.
A 20-minute ride in a coracle that can carry four people is charged Rs 400.
Recently, three brand new boats were introduced in a grand launching ceremony. In the Maha language, such big boats are called the 'jaha thoni.'
A trial race was held at the UAE emirate this year which proved to be a big success.