Sudan’s paramilitary unleashed drones on the Red Sea city of Port Sudan early Tuesday, hitting key targets there, including the airport, the port and a hotel, military officials said. The barrage was the second such attack this week on a city that had been a hub for people fleeing Sudan's two-year war.

There was no immediate word on casualties or the extent of damage. Local media reported loud sounds of explosions and fires at the port and the airport. Footage circulating online showed thick smoke rising over the area.

The attack on Port Sudan, which also serves as an interim seat for Sudan's military-allied government, underscores that after two years of fighting, the military and the paramilitary Rapid Support Forces are still capable of threatening each other’s territory.

The RSF drones struck early in the morning, said two Sudanese military officials, speaking on condition of anonymity because they were not authorized to talk to the media.

Abdel-Rahman al-Nour, a Port Sudan resident, said he woke up to strong explosions, and saw fires and plumes of black smoke rising over the port. Msha’ashir Ahmed, a local journalist living in Port Sudan, said fires were still burning late Tuesday morning in the southern vicinity of the maritime port.

The RSF did not release any statements on the attack. On Sunday, the paramilitary force struck Port Sudan for the first time in the war, disrupting air traffic in the city’s airport, which has been the main entry point for the county in the last two years.

A military ammunition warehouse in the Othman Daqna airbase in the city was also hit, setting off a fire that burned for two days.

When the fighting in Sudan broke out, the focus of the battles initially was the country's capital, Khartoum, which turned into a war zone. Within weeks, Port Sudan, about 800 kilometers (500 miles) to the east of Khartoum, turned into a safe haven for the displaced and those fleeing the war. Many aid missions and UN agencies moved their offices there.

The attacks on Port Sudan are also seen as retaliation after the Sudanese military earlier this month struck the Nyala airport in South Darfur, which the paramilitary RSF has turned into a base and where it gets shipments of arms, including drones.