A security team on a Stolt-Nielsen tanker blew up a pirate boat during a fierce gun battle off Yemen on Sunday.

Security consultancy Ambrey has revealed more details about the attack on the 32,800-dwt Stolt Apal (built 2016), while downplaying reports of a second suspicious approach in the area.

The firm said two blue Yemeni-type skiffs were involved.

The first was seen on the tanker's starboard quarter, after which Stolt Apal altered course.