Two oil tankers were damaged
when they collided in the English Channel 20 miles off the coast of West Sussex.
One of the tankers, the MV Shakhdag,
was carrying 44,000 metric tons of diesel oil while the MV Willy was unladen.
The Maritime and Coastguard Agency said
there were no reported leaks from the Maltese-flagged Shakhdag,
but the MCA counter pollution team was on alert.
Nobody was hurt in the incident, which took place south of Shoreham.
Dover Coastguard identified a collision
between two vessels on its radar screens at about 1120 BST on Friday.
An MCA spokesman said only "minor" damage was caused.
The Willy, carrying 13 people, suffered a split midships
in its cargo tanks and is now returning to Amsterdam for repairs.
It had been en route to a refinery at Stanlow on the River Mersey.
An MCA surveyor has been airlifted on board the Shakhdag
by the coastguard helicopter Victor Alpha from Lee-on-Solent.
The 145ft-long (44.2m) vessel, with 21 people on board,
"sustained some superficial damage to her main deck on the stern
and some upper deck equipment".
It is being inspected to ensure it can continue to Portland in Dorset to discharge its cargo.