(CNN) The two sides battling for control of the Libyan capital Tripoli have engaged in "shameful" attacks on civilian neighborhoods that could amount to war crimes, Amnesty International said .

Renegade Field Marshal Khalifa Haftar, who has been praised by President Donald Trump, commands the Libyan National Army, which in April began an offensive to seize the city from the United Nations-backed Government of National Accord.

Libya has been plagued by violence since the ouster and killing of longtime strongman Moammar Gadhafi in 2011.

More than 400 people have been killed in the latest offensive and over 2,000 wounded, according to the World Health Organization. The UN's humanitarian affairs office said more than 60,000 people have fled their homes.

Fighters loyal to Haftar are imprisoned by forces from the Government of National Accord in Ain Zara on April 11.

Fighters loyal to Haftar are imprisoned by forces from the Government of National Accord in Ain Zara on April 11.

Smoke rises from an airstrike behind a tank and improvised fighting truck belonging to forces loyal to Libya's Government of National Accord, during clashes in Wadi Rabie, south of Tripoli, on April 12.

Smoke rises from an airstrike behind a tank and improvised fighting truck belonging to forces loyal to Libya's Government of National Accord, during clashes in Wadi Rabie, south of Tripoli, on April 12.

A fighter loyal to Libya's Government of National Accord waves from a crater reportedly caused by an airstrike west of the city of Aziziyah, southwest of Tripoli, on April 14.

A fighter loyal to Libya's Government of National Accord waves from a crater reportedly caused by an airstrike west of the city of Aziziyah, southwest of Tripoli, on April 14.

Damaged vehicles are seen after forces led by Haftar carried out rocket attacks in the Abu Salim neighborhood in Tripoli on April 17.

Damaged vehicles are seen after forces led by Haftar carried out rocket attacks in the Abu Salim neighborhood in Tripoli on April 17.

Government of National Accord fighters fire during clashes with Haftar's troops south of Ain Zara on April 20.

Government of National Accord fighters fire during clashes with Haftar's troops south of Ain Zara on April 20.

Libyans pray by the bodies of Government of National Accord fighters during their funeral in Tripoli on April 24.

Libyans pray by the bodies of Government of National Accord fighters during their funeral in Tripoli on April 24.

Government of National Accord troops move into position during clashes with Haftar's forces on April 25.

Government of National Accord troops move into position during clashes with Haftar's forces on April 25.

A fighter loyal to the Government of National Accord stands on a rooftop as smoke rises in the distance on April 29.

A fighter loyal to the Government of National Accord stands on a rooftop as smoke rises in the distance on April 29.

Government of National Accord forces play an online video game on their phones during a break from fighting, in a military base in Tajoura, on May 1.

Government of National Accord forces play an online video game on their phones during a break from fighting, in a military base in Tajoura, on May 1.

Government of National Accord forces are seen during clashes with troops loyal to Haftar at the Al-Yarmook frontline in Tripoli on May 9.

Government of National Accord forces are seen during clashes with troops loyal to Haftar at the Al-Yarmook frontline in Tripoli on May 9.

Libyans call for an end to fighting during a demonstration against Haftar in Tripoli's Martyrs Square on May 3.

Libyans call for an end to fighting during a demonstration against Haftar in Tripoli's Martyrs Square on May 3.

Government of National Accord fighters carry a wounded comrade during a battle on May 21 in the Salah al-Din area, south of Tripoli.

Government of National Accord fighters carry a wounded comrade during a battle on May 21 in the Salah al-Din area, south of Tripoli.

Workers operate on high voltage towers on May 23, after they were damaged by fighting.

Workers operate on high voltage towers on May 23, after they were damaged by fighting.

Government of National Accord forces are pictured near the frontline on June 1.

Government of National Accord forces are pictured near the frontline on June 1.

Government of National Accord Prime Minister Fayez al-Sarraj, fourth from right, performs Eid al-Fitr prayers at Martyrs Square in Tripoli on June 4.

Government of National Accord Prime Minister Fayez al-Sarraj, fourth from right, performs Eid al-Fitr prayers at Martyrs Square in Tripoli on June 4.

Government of National Accord fighters open fire from their position in the al-Sawani area south of Tripoli during clashes with forces loyal to Haftar on June 13.

Government of National Accord fighters open fire from their position in the al-Sawani area south of Tripoli during clashes with forces loyal to Haftar on June 13.

A fighter loyal to the Libyan Government of National Accord checks a building near the Yarmouk military compound, south of Tripoli, following airstrikes on July 1.

A fighter loyal to the Libyan Government of National Accord checks a building near the Yarmouk military compound, south of Tripoli, following airstrikes on July 1.

Bloodstains are seen on a police car at the scene of the airstrike on the migrant detention center.

Bloodstains are seen on a police car at the scene of the airstrike on the migrant detention center.

A policeman is seen at the site of an airstrike which hit a migrant detention center in the Tajoura suburb of the Libya's capital, Tripoli, on Wednesday, July 3.

A policeman is seen at the site of an airstrike which hit a migrant detention center in the Tajoura suburb of the Libya's capital, Tripoli, on Wednesday, July 3.

Trump was strongly criticized for praising Haftar last month as his forces moved in on the capital. The White House's official readout of a phone call between Trump and Haftar, who holds US citizenship, made no mention of the offensive on Tripoli, which Secretary of State Mike Pompeo had criticized earlier in April.

"As the battle for Tripoli unfolds, the warring parties have displayed a shameful disregard for civilian safety and international humanitarian law by carrying out indiscriminate attacks on residential neighborhoods," said Magdalena Mughrabi, Amnesty International's deputy Middle East and North Africa deputy director.

"Such reckless attacks could have devastating consequences for civilians and strengthen the need for the International Criminal Court to expand its investigations into possible war crimes by all sides in Libya's conflict."

Amnesty International said satellite images and witness testimony indicated that "densely populated residential areas in the Abu Salim district of Tripoli were indiscriminately attacked with rockets during an episode of intense fighting between 15-17 April."

Haftar's forces and a local militia affiliated with the Government of National Accord blamed each other for the indiscriminate attacks in southern Tripoli. Residents interviewed by Amnesty International told the NGO they believed Haftar's forces were responsible.

"Deliberate attacks on civilians and civilian property, and indiscriminate attacks that kill or injure civilians, amount to war crimes. All sides have an absolute obligation under international law to protect civilian lives and to clearly distinguish between civilians and fighters during their attacks," Mughrabi said.

Libya's Khalifa Haftar salutes during a military parade in the eastern city of Benghazi on May 7, 2018.

Haftar took part in the coup that brought Gadhafi to power 50 years ago. Now in his mid-70s, he has sent his forces across the desert from Benghazi in a bid to seize the country for himself.

Haftar's main supporters are Saudi Arabia, Egypt and the United Arab Emirates.

The Government of National Accord has the recognition of the United Nations but has difficulty enforcing its rule beyond the capital. It is hobbled by internal feuds and depends for security on rival militia, most of whom have an Islamist complexion.