Suspected Islamist insurgents attacked a convoy of fleeing civilians, including foreign workers, as fighting continued in a northern Mozambique town that is near a number of gas projects, security and diplomatic sources said.

At least one person was killed and a number wounded in Friday's attack, according to three sources and three organizations with employees inside a hotel where people have been taking refuge in the town of Palma.

French energy group Total said on Saturday it had postponed the restart of work at its site near Palma, a logistics hub adjacent to gas projects worth $60 billion. No project staff were among the victims of the fighting, it said.

The attack on Palma began just hours after Total said on Wednesday that it would resume work at its $20-billion project after halting operations in January due to security concerns.

Nearly 200 people had been sheltering in the Amarula Palma hotel during the attack, according to three diplomats and one of the organisations with people inside.

They included a Spanish resident and other foreigners who locked themselves in a protected room in the hotel, a Spanish diplomatic source told Reuters. Spain's foreign ministry confirmed there had been a Spanish citizen in Palma who managed to flee the town.

Before the ambush, rescue efforts had been underway with at least 20 people flown to safety in helicopters, said Lionel Dyck, who runs Dyck Advisory Group, a South African private security company that works with Mozambique's government.

On Friday afternoon, some people attempted to escape in a convoy of vehicles but were ambushed just outside the hotel, according to Dyck, two diplomats and the organizations with people inside.

Dyck said his helicopters evacuated more than 20 survivors on Saturday.

SOME STILL MISSING
Reuters could not independently verify the accounts. Most communications with Palma are down. Officials at Mozambique's foreign ministry, defence ministry and provincial government did not immediately respond to calls or had their phones switched off on Saturday. The national police said they were evaluating the situation, without providing further details.

Mozambique's government said on Thursday that security forces were working to restore order in Palma.

The province of Cabo Delgado, where the town is located, has since 2017 been the target of a simmering Islamist insurgency linked to Islamic State.

It was not immediately clear how many people, if any, remained in the Amarula Palma hotel on Saturday and how many were missing. Contacted via Facebook, the hotel said it could not give any information.

South Africa's foreign ministry said some of its citizens had been affected by attacks on foreign nationals on Friday. It did not elaborate.

Cindy Cooke, a South African whose 21-year-old stepson Francois van Niekerk is in Palma, was frantically trying to get information.

His family had not heard from him since Wednesday, though rescuers had been to his location on Saturday and he was not there, she said.

"It's scary. Being there is no joke. They (the insurgents) are ruthless, just ruthless," she said.

Beheadings have been a hallmark of attacks by the insurgents, whose rebellion is rooted in local issues from poverty and unemployment to perceived corruption and religious discrimination.

Portugal's foreign ministry said one of its nationals had been injured in the fighting but did not specify the circumstances. The person had since been rescued, and its embassy in Maputo was working to identify other Portuguese nationals who needed support, the ministry said in an email.

New York-based Human Rights Watch said it spoke to seven people in Palma before communications were cut on Wednesday. They described people fleeing as gunshots rang out, bodies in the streets and insurgents firing at both people and buildings, the group said in a statement.