One of India's busiest ports is likely to remain closed for three days after a collision between two cargo vessels on the approach to the harbour, an industry official said on Tuesday.
Hundreds of containers from one of the stricken ships have spilled into the sea, with diesel oil and fuel spreading towards the shore.
The official, who asked not to be identified, told AFP that Mumbai's Jawarhalal Nehru Port (JNP) was expected to be shut until the clean-up operation in the shipping lane was completed.
The nearby Mumbai Port, which also handles cargo, was also shut after the collision between two Panamanian-registered container ships on Saturday morning.
A shipping trade body warned that the closures could affect business for weeks to come.
"The short-term impact is that at the moment we have two ports constituting 40 percent of India's maritime trade closed," the vice-president of the Western India Shippers' Association, Mr R. Venkatesh, told AFP.
"That's really going to have a cascading effect."
A total of 12 ships are unable to leave the JNP and 13 were anchored outside the port until free berths became available, Mr Venkatesh added.
No figures were immediately available for Mumbai Port.
Venkatesh said that some freight carriers had already suspended bookings and a knock-on effect was likely on shipping charges.
India's shipping ministry said in a statement on Monday evening that the hazard posed by stray containers in the channel off Mumbai posed a risk to maritime traffic, prompting the halt on ship movements.
Hundreds of containers from one of the ships, the MSC Chitra, which is listing badly at a 60-degree angle, have spilled off deck into the Arabian Sea and diesel fuel and oil spread towards the shore.
Six coastguard ships and a helicopter were deployed to contain the spill, amid fears that the oil and hazardous chemicals in some of the containers could damage marine life and the surrounding coastline.
Fishing has been suspended in the area, while local people have been warned not to eat locally-caught seafood because of contamination fears.
Salvage teams are working to either submerge the containers or tow them to safety. A decision is also expected on whether to right the MSC Chitra or remove its remaining oil into barges, the ministry said.
The MSC Chitra was carrying 2,700 tonnes of fuel oil and 300 tonnes of diesel oil. Some 1,200 tonnes of fuel oil was in the ruptured tanks on the ship's port side.
The coastguard said that leaking oil from the stricken vessel had reduced to a trickle.