CAIRO, July 30 (Xinhua) -- Preliminary investigations indicated that a drone attack caused Wednesday's fire on two gas-related vessels at Damietta Port on the Mediterranean coast, Egyptian authorities said Thursday.

"No party has claimed responsibility for the incident," the Egyptian cabinet said in a statement.

The investigations are underway to determine the circumstances surrounding the incident, and the government is taking necessary measures to safeguard Egypt's interests and national security, it said.

Meanwhile, the Damietta Port Authority said on Thursday that operations were continuing at full capacity, with vessel arrivals and departures, cargo loading and unloading, and other activities proceeding normally.

"The port continues to provide its maritime and logistics services around the clock without interruption," the authority said.

Egypt's Ministry of Petroleum and Mineral Resources said Wednesday that a fire broke out on a regasification vessel and a storage vessel at the port and was brought under control immediately, with no casualties reported.