TRIPOLI, April 3 (Xinhua) -- The Libyan UN-backed government on Monday launched a sudden military operation to hunt down the remnants of Islamic State (IS), more than a year after IS was expelled from its former stronghold in Sirte.

The military operation, known as Homeland Storm, was announced by the government spokesman Mohamed Al-Sallak, during a press conference in Tripoli.

"According to the instructions of Prime Minister Fayez Serraj, a military operation called Homeland Storm was launched Monday dawn to pursue the remnants of terrorist groups, mainly IS," said Sallak.

The operation started from the eastern city of Misurata, 200 km east of the capital Tripoli, covering valleys and desert areas of the nearby cities of Sirte, Bani Walid and Tarhouna, according to the spokesman.

"The operation will involve all government army units to pursue the remnants of terrorist organizations, especially IS, and to eliminate their continuous threats to the country's national security," he said.

Mohammed Abdullah, a member of the eastern-based Parliament, believes that any military operation to pursue remnants of terrorist groups must be done with cooperation, as it is the battle of all Libyans.

"IS remnants are moving freely between Sirte and Misurata and to the southeast of Tripoli. The terrorists are moving in an area of more than 400 square km, a vast area that requires military and intelligence work to weaken their movements after the continuous rise of their suicide operations," Abdullah told Xinhua.

Abdullah stressed the importance of cooperation between the military forces in the east and west to generate effective outcome to eliminate terrorism.

IS remnants are mostly active in the desert of Sirte, due to its rugged valley nature, as well as in the southern Libyan desert cities.

Later in 2016, forces allied with the Libyan government defeated IS affiliates and expelled them from Sirte, some 450 km east of Tripoli, after fierce fighting that killed more than 700 government troops and more than 2,000 IS fighters.

The remaining IS militants fled to the southern valleys and mountainous areas ever since, and have carried out suicide attacks on security checking points.

The air force of the eastern-based army, led by General Khalifa Haftar, also targets IS sites and gatherings near Sirte.

"The alliance of al-Qaida with the Islamic Maghreb and IS have made the government learn the importance of moving quickly to pressure the terrorists and prevent them from striking hard, especially after the recent U.S. airstrikes on terrorists in Ubari (southern Libya)," said Mohammed Khoja, an analyst on terrorist groups.

"Airstrikes carried out by a U.S. drone on a meeting of al-Qaida in Ubari caused a state of panic, movement and rapid response among the terrorists. A suicide bomber attacked the army forces in the eastern city of Ajdabiya, an evidence of the simultaneous attacks between the two organizations, whose movements began to be homogeneous and similar," Khoja explained.

"This is a sign that requires rapid intervention to counteract any plans of terrorist leaders against the government or the army forces," he said.

IS claimed responsibility for a suicide attack on a security checking point near Ajdabiya on Thursday, which killed six people and wounded more than 10 others.

U.S. airstrikes occasionally target remnants of terror groups in Libya. A U.S. drone launched airstrikes later in March on a terrorist site in the southern city of Ubari.

The government said the strikes were carried out based on coordination between Libya and the United States against al-Qaida leaders.

It also confirmed that the joint coordination with Washington targeted terrorist leaders during a meeting in a house in Ubari, killing two of them.

The U.S. Department of Defense later revealed that one of the killed terrorists was a man named Mousa Abu Dawud, a senior leader of al-Qaida in the Islamic Maghreb with Algerian nationality.