The UK Maritime Trade Operations received a report of a ship being attacked by a drone south west of Veraval, India, it said on Saturday.

The attack caused an explosion and fire on a ship it did not identify but no casualties were reported, the UKMTO said. Authorities are investigating the incident. The maritime agency also advised vessels to transit the area with caution.

It is still unclear who is responsible for the attack, but it raises the question of whether a new risk area may open up. In recent weeks, attacks by Iran-backed Houthi militants on merchant ships in the Red Sea have created chaos in an area that accounts for some 12% of global maritime trade. The world’s major container and oil shippers have been rerouting vessels away from the Red Sea as Houthi militias stepped up attacks in response to Israel’s war with Hamas. 

A.P. Moller-Maersk A/S, the world’s second-largest container line, says the diversions may last for months. Meanwhile, the US has formed an international naval coalition which is intended to serve as a “highway patrol” to protect shipping in the Red Sea from attacks.