Mumbai harbour reopened to traffic on Thursday five days after a collision between cargo ships, a news report said, according to dpa. The Indian navy escorted 12 freighters in and out of the Jawaharlal Nehru Port after authorities cleared a navigational channel of the Arabian sea of the containers, fuel oil and lubricants that ended up in the water due to the collision. The Nehru port is India's largest port, handling up to 60 per cent of the country's containers by volume. Located on India's west coast, Mumbai is India's financial hub and has two ports. "The Indian Navy commenced escorting a convoy of merchant ships in and out of Mumbai port from 1000 hours," defence spokesman Captain M Nambiar told the PTI news agency. The freighters received navigational guidance from a helicopter, while a minesweeper with two survey boats equipped with sonar scanners ensured that the channel was clear, the report said. The Panama-registered cargo ship MSC Chitra sprang a leak after colliding with another vessel outside the harbour Saturday. Oil escaped from two of the ship's fuel tanks, and containers fell off as the vessel listed, posing a navigational hazard. As many as 31 of the 1,219 containers on board the MSC Chitra held hazardous chemicals including pesticides, PTI news agency reported. An estimated 400 to 500 tons of fuel oil may have spilled from the vessel which was carrying 2,662 tons. Port authorities, India's coast guard and foreign experts were jointly carrying out the salvage operation. The government of Maharashtra, of which Mumbai is the capital, has warned against fishing or eating fish until the oil slick was brought under control. Government officials said an analysis of water samples so far showed no contamination from hazardous chemicals or pesticides. But news channels reported that oil was sighted on the shore in Mumbai and had affected mangroves in some areas. The Bombay Natural History Society has been asked to assess the pollution across the coastline and is expected to submit its report in the coming days.