BENGHAZI, Libya (Reuters) - Libyan forces advanced into several neighborhoods in Derna on Monday after stepping up a military campaign to oust rivals from the eastern city, a spokesman and residents said.

The advance followed heavy shelling and air strikes in recent weeks as the Libyan National Army (LNA), an eastern-based force loyal to Khalifa Haftar, launched a ground campaign around Derna.

The LNA has long encircled the city of 125,000, the last in eastern Libya to elude its control. It is held by the Derna Protection Forces, formerly known as the Derna Mujahideen Shura Council, a coalition of Islamists and other anti-Haftar combatants.

Early on Monday, LNA forces entered Derna from both the eastern and western coastal roads and took control of the Shiha and Bab Tobruk districts, advancing to within one kilometer of the port, one of the operation’s commanders, Salem al-Rafadi, told Reuters.

Photos shared by a resident appeared to show soldiers and military vehicles advancing along largely deserted streets.

Haftar says his men are fighting to rid Derna, a city around 266 km (165 miles) from the border with Egypt, of “terrorists”. Opponents accuse him of subjecting the city to urban warfare to expand his power after destroying parts of Benghazi in a similar campaign.

In a speech broadcast on the LNA’s social media pages on Monday, Haftar announced the “second phase of the liberation of Derna”.

“In good news for all honorable Libyans, the hour of victory is approaching, and the announcement of the city of Derna rid of terrorism, secure and at ease under the protection of the armed forces and security units,” Haftar said.

The fighting in Derna, which escalated again last week, encroached into densely populated areas, and since May 16 at least 17 civilians including two children have been killed. Among them were seven people who died in an explosion as they tried to leave Derna on May 30, the U.N. said on Friday.

The LNA opposes an internationally recognized government in Tripoli, and is linked instead to a government and parliament based in the east.

Its surge in Derna overshadowed high-level talks in Paris last week that tried to chart a way out of Libya’s turmoil and set a goal of holding elections in December.