Two ships, one of them a U.S.-owned natural gas storage tanker, caught fire after an explosion at an Egyptian port on Wednesday, broadening the conflict in the Middle East.

Three marine tracking companies reported the incident. One of the companies said the explosion, in the Egyptian Mediterranean port of Damietta, had been caused by a drone attack, though there was no official confirmation from Egyptian authorities or the ships’ owners.

The attack isn’t likely to affect global energy markets as much as those elsewhere in the Middle East because Egypt is not a big exporter of natural gas.

Kpler, a maritime tracking firm, said both vessels had been moved away from the Damietta Port, which is near the Suez Canal on Egypt’s Mediterranean coast. There were no confirmed injuries or deaths, Egypt’s ministry of petroleum said on social media.

Joshua Hutchinson, the chief commercial officer of Ambrey, another maritime tracking firm, said in an interview that the explosion was believed to be caused by a drone attack, which hit at least one of the ships. Ambrey has not identified the source of the attack.

Two Iranians, who asked not to be named to discuss security matters, said the explosion was a drone attack designed to show that global shipping and energy supplies could be more deeply disrupted if Iran chose to escalate. The individuals did not say whether Iran or an Iran-allied militia in the region had launched the attack, or from where.

President Trump told reporters in the Oval Office on Wednesday that he had been briefed on the explosion and implied that Iran was responsible, without offering details. He said the incident was “more of the same” and that the United States was “going to be hitting them very hard, because it’s our turn to hit them.”

By attacking ships in the Mediterranean, Iran could further disrupt trade. Shipping companies would have to assess the risks of using Egyptian ports. Since the Iran war began at the end of February, many ship operators have avoided the Red Sea and the Persian Gulf.

The Energos Winter, the U.S. storage tanker that caught fire, belongs to Energos Infrastructure, a U.S. company based in Stamford, Conn. Jonathan Chia, a representative for Energos Infrastructure, said the company had not been able to determine whether Energos Winter had been hit by a drone. Mr. Chia said that all the crew members had been accounted for, and that none of them had been injured.

Footage circulating on social media and verified by The New York Times showed tugboats hosing down the Energos Winter with water at the Damietta Port.