Yemen's Houthis are targeting ships on high seas

Houthi militants showed in late April that they can expand their war on international shipping far beyond the Red Sea.

The container ship MSC Orion came under a drone attack on the night of April 26 as it was steaming in the Indian Ocean southeast of the Horn of Africa, the continent's eastern-most tip. The attack only caused minor damage and did not harm any crew. But the distance involved was unprecedented.

The Houthis have wreaked havoc against international shipping in the Red Sea with ballistic missiles and exploding drones, and threatened in March they could menace ships that avoided this route by going around Africa's southern Cape of Good Hope, a much longer and more expensive voyage.

The long-range attack on the Orion appears to have been a one-off but is still unprecedented, an expert on drone warfare said.

Searching and targeting ships in international waters is also another escalation from the group's attacks near the Red Sea. The Houthis are most likely exploiting the self-reporting of merchant ships to target them.

Ships may opt for alternative or longer routes to avoid these attacks, and while this may reduce the number of attacks, that would also have a disruptive impact on shipping of the kind the Houthis would welcome.