By Ayman al-Warfalli and Ahmed ElumamiTRIPOLI, Aug 11 (Reuters) - Libyan firefighters continued to battle a blaze at the Zawiya refinery complex on Tuesday, according to two engineers at the site, with state oil firm NOC saying it could declare force majeure if drone attacks on oil assets in the city continued.

A drone hit a naphtha tank at Libya's Zawiya refinery on August 8, causing a contained leak. NOC Chairman Suleman confirmed no fire or injuries.

The incident came two days after a drone crashed into an untreated naphtha tank at the Zawiya refinery early on Saturday, causing a leak that staff managed to control.