CAIRO (Reuters) - Forces aligned with Libya’s internationally recognized government seized two towns west of the capital Tripoli on Monday after heavy clashes and drone strikes, military sources and residents said.

If held, the towns of Surman and Sabratha would represent a significant gain for forces trying to fight off a year-old campaign against Tripoli by rivals loyal to eastern-based commander Khalifa Haftar.

It could also relieve some pressure for the Tripoli-based Government of National Accord (GNA), which has been struggling with water and power cuts in recent days on top of the loss of revenue from blockaded oil ports in the east.

Libya has been split into rival factions based in Tripoli and the east since 2014, each with parallel sets of institutions. Over the past year fighting has escalated and drawn in greater foreign involvement as Haftar’s Libyan National Army (LNA) attacked the capital.

On Monday, residents and military sources from both sides said GNA-aligned forces had taken full control of Surman, about 60km (37 miles) west of Tripoli, and Sabratha, just west of Surman. The area has been a hub for migrant smuggling and Islamist militants in recent years.

Videos circulating online showed dozens of GNA fighters shooting in the air near a roundabout in central Sabratha.

The city’s pro-LNA municipal council said dawn drone strikes had killed and wounded a number of fighters. “The sound of the drones above the city was like a beehive,” said one resident. “There were many air strikes.”

Prisoners were freed from a security building in Surman, according to an LNA military source.

Fractured ground forces have struggled to make breakthroughs around Tripoli, often relying on help from foreign fighters and drones. The LNA has received backing from the United Arab Emirates, Jordan, and Russia, according to U.N. experts and diplomats, while the GNA is supported by Turkey.

Recent calls for a ceasefire to let the divided country try to counter the spread of coronavirus failed to halt the violence. Libya has so far reported 25 coronavirus cases, including one death.

In Tripoli on Monday, loud explosions and heavy artillery fire could be heard across the city throughout the day. On Sunday there were heavy clashes south of Misrata, a major base of military support for the GNA.

Power supplies to western areas have been cut since Thursday, when a gas valve was shut in what the National Oil Corporation called an “illegal closure”.

Water supplies to the capital, turned off by an armed group last week, have been switched back on after mediation by local elders, a senior official for Libya’s Great Man Made River, Ahmad al-Deeb, told Reuters.