Authorities are planning a damage assessment Wednesday on a barge loaded with diesel fuel that ran aground outside Portsmouth Harbor late Tuesday.

A tugboat moving the barge, which was carrying 80,000 barrels of low-sulfur diesel, was maneuvering to start pushing from the stern, when the barge drifted into a shoal, the U.S. Coast Guard said.

Nobody was injured. It appears there was no serious damage to the double-hulled barge and no fuel leaked, the Coast Guard said. The barge was able to be moved off the shoal and berthed where it is expected to offload its cargo.

The captain of the tugboat, the Mediterranean Sea, was given drug and alcohol tests as required. The alcohol test was negative and the drug test results are pending, the Coast Guard said.

A more extensive assessment was conducted during the slack tide at about 1 p.m.

The grounding happened off Fort Point at the entrance to the harbor, the Coast Guard said.