A rocket attack Sunday night damaged a storage tank at a refinery complex in Erbil — highlighting what appears to be an escalating threat against the Iraqi Kurdish company KAR Group, which operates the refinery and other critical energy projects in Iraqi Kurdistan.

“The fire was extinguished at dawn on Monday,” said an official at the Kirkuk-based North Oil Company (NOC), which supplies the refinery with some of its crude feedstock. An official at the refinery also confirmed the attack.