Owners had been used to gunfights shutting down ports and occasionally targeting their ships in Libya. But fighter jets dropping bombs on oil tankers mark a new level of violence in the war-torn country, sparking concerns about whether ships should be sent in harm’s way there.

Two people were killed on 4 January when a Libyan war plane bombarded the 28,610-dwt Araevo, (built 1991) a Greek-owned products tanker lying at anchor some three kilometres (two miles) off the port of Derna in the east of the country.