MAPUTO (AFP) - Mozambique's military said on Sunday (April 4) that a "significant" number of militants were killed during a battle over a key northern town and gas hub captured by the Islamic State in Iraq and Syria (ISIS) militant group last month.

Palma was seized by the Islamists during coordinated attacks on March 24, in what was seen as the biggest escalation of the insurgency ravaging the north of the African nation since 2017.

The true death toll is not yet known, but thousands were displaced from the town of some 75,000 and French energy giant Total suspended operations at its multibillion-dollar plant.

On Sunday, the army escorted officials and journalists through the ravaged town, claiming a "significant" number of militants had been killed, and that they had now secured the surrounding area.

Commander Chongo Vidigal, leading the military operation to regain control of the town, said the area was "safe", but fell short of declaring the army had regained control.

"The airfield area was the only one we needed to clear and we did that this morning. It's completely safe," Commander Vidigal said.

"I think that it is a significant number of terrorists who were shot down," he said, adding they would clarify the exact number later.

Last week, the government said dozens of civilians had died during the fighting, but Commander Vidigal said they had not finished counting the bodies.

In the first footage of the aftermath, state television broadcast videos of soldiers hastily pulling black plastic sheets over the dead on the streets.

A few civilians were collecting bags of grain, while one man was shown trying to clear a destroyed stall.

The town's hospital was destroyed, as were commercial banks and the state prosecutor's office.

Commander Vidigal said the Total gas plant, which the company abandoned last Friday, was secure.

"The facilities are safe, they are protected," he explained.

Total pulled out its staff last Friday, while the United Nations suspended civilian evacuation flights over security concerns.

More than 11,000 civilians are known to have fled Palma in recent days, according to the UN.