SAN DIEGO â€"  The U.S. Navy says an amphibious assault ship and a replenishment tanker collided in the Pacific Ocean but there were no injuries and no fuel spills.

A Third Fleet public affairs statement says the collision between the assault ship USS Essex and the oiler USNS Yukon occurred at midmorning Wednesday approximately 120 miles off Southern California.

The Navy says an apparent steering malfunction occurred as Essex approached the Yukon for replenishment while under way.

Neither ships' fuel tanks or systems were compromised, but the Navy says a full assessment of any damage is continuing.

The Essex is due to return to San Diego on Thursday after 12 years based in Sasebo, Japan.