MAIDUGURI, Nigeria (AFP) - Thousands of people fleeing the latest Boko Haram violence have poured into the embattled Nigerian city of Maiduguri, putting pressure on camps for the displaced as rescue workers try to cope with the influx.
A group of 5,000 people, most of them women and children, reached the Borno state capital on Monday after escaping the extremists' weekend takeover of the nearby town of Monguno, officials said.
"We trekked throughout Sunday through the bushes and did not relent, even at night," said Karimu Usman, a Monguno community leader, who told reporters he led a group of 300 others on the overnight march.
Many of those who fled only arrived after escaping a massive Boko Haram attack on the town of Baga earlier this month, which reportedly killed hundreds of people, destroyed thousands of homes and prompted global outrage.
Boko Haram has taken over much of northeast Nigeria and the insurgents seem capable of attacking large population centres at will.
Election officials have admitted that it will be impossible to organise polling across much of the northeast for the country's Feb 14 vote.
- Cholera outbreak -
The United Nations has said there are more than one million internally displaced people (IDPs) in the region, and hundreds of thousands of them have sought sanctuary in Maiduguri, swelling a population estimated last year at over two million.
Faisal Gaal, project coordinator in Borno for the medical charity Doctors Without Borders (MSF), said the IDP population in Maiduguri is reaching unsustainable levels and straining resources.
There were 7,000 cases of cholera recorded in the city between September and December, half of them in IDP camps, and sanitation remained dire, according to MSF.
Gaal said keeping track of those displaced has been a challenge because of the relentless attacks, which has forced people to run from town to town in search of refuge.
One elderly man ran from Baga, in the far north of Borno, and wandered confused and alone in the bush for 17 days before local hunters guided him to Monguno, 137km by road from Maiduguri.
Gaal said he met the man in Monguno on Friday and had planned to visit him again this week "but unfortunately Monguno was taken" by Boko Haram on Sunday.
"We don't know where he is now," Gaal told AFP.
The MSF official said mothers on the run were afraid their sons would be conscripted to join the vigilante groups who are helping the military fight Boko Haram.
One woman in Monguno "was dressing her son as a girl to keep him from being drafted", Gaal said.
While some mothers are taking measures to protect their sons, a growing concern is the number of children arriving in camps without parents, said Abubakr Bashir Bakri, MSF's head of mission in Nigeria.
"There are many of them... We are concerned about (their) psychological state," he added.
- Humanitarian crisis -
One woman who escaped, Saudatu Isufu, said Monguno was gripped by "a humanitarian crisis" but the town was currently inaccessible to aid groups following the Boko Haram takeover.
"People trapped there need to be rescued," she told reporters in Maiduguri.
Those who escaped needed to pass a security check before being allowed to enter Maiduguri, with the military worried that insurgents would try to infiltrate the state capital by blending in among the IDPs.
Abdulkadir Ibrahim, of Nigeria's National Emergency Management Agency (NEMA), described the group that reached Maiduguri as "disturbed and hungry" and said rescue workers were trying to stabilise them.
Lack of relief staff on the ground has been a chronic problem in the northeast. MSF and other organisations have said they would like to reinforce their presence, especially in Maiduguri.
"The increasing number of people puts pressure on us (and) requires a lot of resources," Bakri said.
But with violence escalating and attacks impossible to predict, sending large teams to Borno was likely to be unrealistic in the short-term, he added.