Armed guards on a Stolt-Nielsen chemical tanker have been involved in a brief gun battle with pirates who attacked the vessel as it sailed through the Gulf of Aden on Sunday.

Stolt Tankers confirmed earlier intelligence reports that the UK-flagged, 32,798-dwt Stolt Apal (built 2016) suffered minor damage during the incident.

There were no casualties reported on board the tanker, which is now continuing its laden voyage towards the Suez Canal.

The attack is thought to be the ninth in the region this year, although the overall level of piracy in the area is far below that seen in the first half of the last decade.

“[The] Stolt Apal was approached by two skiffs running at high speed with six armed pirates,” Stolt Tankers said in a statement.

“After multiple warning shots were fired by the armed guard team aboard Stolt Apal, the skiffs opened fire on the ship. The armed guard team returned fire, disabling one skiff, which ended the pursuit."

No injuries

Stolt said the incident, which occurred 75 nautical miles (139 km) south of Yemen, saw the vessel’s bridge area sustain minor damage from bullets but there were no injuries, no pollution and there was no impact on its cargo.

A coalition warship responded and the Stolt Apal has resumed its voyage, the company added. The vessel was reported to be sailing at 13 knots.

Security consultancy Ambrey said one skiff was observed following the tanker's course at a distance of two nautical miles.

After adjusting course, a second skiff was seen approaching from a distance of three nautical miles at about 23 knots.

The armed guards opened fire when one closed to 800 metres from the tanker.

Risk consultancy Dryad Global said that although the nature of the attack remained unclear, it is ninth reported incident in the Gulf of Aden this year.

“This latest incident occurred 58 nautical miles east of a previous suspicious approach, where several skiffs were reported to have closed within one nautical mile of a vessel transiting westbound,” Dryad said.

The incident is also 117 nautical miles west of a reported attack against a Saudi-flagged vessel.

In recent months, most security attention in shipping has been focused on West Africa after a string of crew kidnappings.