Fighters linked to ISIL have intensified attacks recently in the gas-rich Cabo-Delgado province.
The United Nations has launched an appeal for $254m to help hundreds of thousands caught in violence in northern Mozambique linked to the ISIL (ISIS) group that has gathered pace this year.
The ISIL-linked groups unleashed a violent campaign in the gas-rich Cabo Delgado province in 2017 that has since killed more than 2,300 people and forced hundreds of thousands to flee.
The UN said many people fled with just the clothes they were wearing and warned that 1.1 million people would need help next year.
“They lost their belongings, their livelihoods, their future,” said Myrta Kaulard, the UN’s humanitarian coordinator in the country, on Friday.
“Humanitarian assistance is vital to alleviate their suffering.”
The fighters have launched hundreds of attacks since starting their campaign by killing two police officers in the port city of Mocimboa da Praia in 2017.
The violence escalated this year and the fighters now control swathes of the coast – including strategic ports and cities with gas installations – and have advanced inland.
“Women and girls are at risk of abduction, gender-based violence and exploitation, while boys are at risk of being killed or recruited by armed actors,” said Kaulard, expressing particular concern about those trapped in isolated areas.
Thousands of refugees have poured into nearby towns and cities, staying with relatives or have been taken in by strangers, leaving local services stretched to breaking point, warned the UN.
With the rainy season approaching, many areas hosting those fleeing the violence are expected to flood, ramping up the pressure to find a quick solution.
“The situation in Cabo Delgado is a protection crisis with widespread human rights abuses and disregard for international humanitarian law,” Juliana Ghazi, associate external relations officer at the UN High Commissioner for Refugees (UNHCR), told Al Jazeera.
“The UNHCR remains deeply concerned with the rising number of civilians that have been displaced in northern Mozambique as attacks continue to take place in Cabo Delgado,” Ghazi said.
“Access in some areas of Cabo Delgado also remain limited due to the violence and insecurity.”
Nathan Sales, the coordinator for counterterrorism at the US State Department, said last week the fighters in northern Mozambique belonged to a “committed” affiliate of ISIL and should be seen as a global threat.
Violence spilled across the border into Tanzania in October, prompting the two countries to launch joint military operations.