Two ships ferrying petroleum products collided outside Tamil Nadu's Kamarajar Port on Saturday, but there was no major damage to the ships or oil spill, authorities said.

Shipping industry professionals told IANS it was "providential" that no major damage occurred due to the collision which seems to be due to grave human error.

In a statement, port authorities said the collision took place around 4 a.m. between M.T. BW Maple carrying liquefied petroleum gas and M.T. Dawn Kanchipuram carrying petroleum oil lubricants.

The LPG carrier was outbound while the other was inbound.

"There is no damage like oil spill and no casualty or injury to any person. Both vessels are afloat and anchored. The extent of damage is under assessment," the statement said.

"All top port officials are closely monitoring the situation that is under control. An enquiry has been ordered to find the cause of the accident. All other ship movements are normal."

An Indian Coast Guard official told IANS: "We have issued notice to the ship owners as to their action plan on the spill."

He said as per an aerial survey done by the Coast Guard's helicopter, a very thin sheen of oil was seen on the water surface.

The Coast Guard has sent one of its ships to the spot in case of need, he added.

The Coast Guard said crew of both vessels are reported to be safe.

The port deployed three tugs for immediate assistance and they laid a boom around MT Dawn Kanchipuram to contain the spill, it said.

The coastal security agency said the owner of the vessel/agent have been advised to expedite all repairs and undertake survey of ships for bringing these to the port to facilitate early discharge of cargo.

"The Coast Guard is maintaining a close watch, especially toward marine environment. Presently, there is no damage to the marine or coastal environment," the statement added.

Port Chairman and Managing Director M.A. Bhaskarachar told IANS that he had no additional information on the incident.

Port officials told IANS that the operations at Kamarajar Port is as usual.

The cargo from M.T.Dawn Kanchipuram will be unloaded, a port official said.

"Piloting a ship in and out of harbour is a tricky operation. Further a ship has a lot of inertia and hence it is difficult to stop it," a marine engineer told IANS.

"A ship does not have a brake. Simply put, a ship is slowed by reversing the propellers' rotation," he added.

"It could certainly be said that it was a lucky escape as no major damage has happened to the vessels," Girish Sehgal, LNG Vessel Technical Adviser, told IANS.

He said the collision could have happened mainly due to human error.

Industry professionals said even if the LPG tanker is empty, there is always a risk of explosion due to presence of gas traces in emptied tanks.