Cyclone Eloise, which lost its strength, hit the port city of Beira early on Saturday, but danger of flooding remains.
Fighting around the strategic Mozambique town of Palma entered a second day on Thursday as ISIL-linked fighters occupied and ransacked it despite French energy giant Total claiming it was secure.
Mozambique’s government said the town – in its northernmost province of Cabo Delgado and about 10km (6.2 miles) from gas developments worth $60bn – came under a three-pronged attack on Wednesday and security forces moved in to establish order.
Bodies were visible in the streets, some of them beheaded, and helicopter gunships exchanged fire with the attackers, a security source told Reuters news agency.
The attack came shortly after French oil giant Total announced plans to resume construction at the nearby site of a $20bn offshore gas project.
Defence ministry spokesman Omar Saranga said Mozambique’s security forces (SDS) were “pursuing the enemy’s movement” and working “tirelessly to restore security and order”.
“SDS will do everything to ensure the safety and wellbeing of the population … while continuing to guarantee the protection of economic projects,” he told reporters in the capital Maputo.
Saranga said the number of any casualties and the extent of damage were not yet known, adding mobile communications in the area had been “interrupted”.
Helicopters provided air support as small groups of people fled by road, said the security source, who was involved in the operation to secure Palma.
Total had no immediate comment on the impact of the attack on its operations.
Within a few hours of Total’s announcement, strategically important Palma, which hosts numerous international companies looking to cash in on one of the biggest gas finds in a decade, had been hit with its first major strike.
Mozambique’s forces had not repelled the attack as of Thursday morning and fighting was ongoing, according to sources in touch with the Mozambique government and military officials.
Joseph Hanlon, a researcher and author on Mozambique, said vast mineral wealth in the region had been exploited by an elite few with the majority of residents not reaping any profits, leading to the rebellion.
“It is really a serious threat. One of the reasons the Palma attack is so important is this is the closest they’ve come to the gas project in scale. There were more than 100 insurgents, it was well organised, well-coordinated,” Hanlon told Al Jazeera.
He said reports suggest the attackers pulled out of Palma, but not before robbing two banks and having “taken control of the town for a day”.
Palma is located more than 1,800km (1,120 miles) northeast of Maputo in gas-rich Cabo Delgado province, where authorities have grappled with a brutal rebellion since 2017.
Fighters affiliated with the armed group ISIL (ISIS) have raided villages and towns across the province for years, causing hundreds of thousands to flee their homes.
The violence has killed at least 2,600 people, half of them civilians, according to the United States-based data-collecting agency Armed Conflict Location & Event Data Project.
Amnesty International this month said local people were “caught” between fighters on one side and government security forces and a private militia on the other.
The watchdog accused all three parties of “war crimes” causing hundreds of civilian deaths.
The fighting has also rocked the development of Africa’s largest liquified natural gas (LNG) project off the Afungi peninsula, set to go online in 2024.
Total is the project’s main investor with a 26.5-percent stake. Six other international businesses are also involved, including Italy’s Eni and US major ExxonMobil.
Total was forced to evacuate some staff in January after rebel fighters launched a series of attacks just kilometres from the LNG site.