Boko Haram’s ransacking of villages in northeastern Nigeria during the past three weeks has caused a massive displacement of citizens who are now spilling over the borders of two neighboring countries, with the area quickly becoming the locus of one of the world's biggest humanitarian crises. Nigeria, Chad and Cameroon are pooling military resources to fight the Islamist militant group, but their efforts have failed to stop the mass exodus of hundreds of thousands of people who are now seeking humanitarian assistance.

In its January offensive, Boko Haram has managed to kill more than 2,300 people and displace 1 million-plus from their homes -- which is more than the number of Syrians displaced in the first year of that country's civil war, according to the Migration Policy Center at the European University Institute. In November 2012, there were 300,000 people displaced by the Syrian Civil War, the United Nations High Commissioner for Refugees reported. At that time, the international community banded together to donate millions of dollars in medical aid and food to the refugees. In contrast, the people who are fleeing northeastern Nigeria are getting aid from just a few humanitarian groups with limited resources.

Boko Haram has been slaughtering civilians in Nigeria since 2009, when it announced it would embark on a campaign to create an Islamic caliphate in the country. The militant group killed 700 people that year, but the comparable figure escalated to 7,700 last year and more than 2,300 in the first month of 2015 (so far), according to data compiled by the Armed Conflict Location and Event Data Project, a research effort mostly focusing on African conflict with ties to the Robert S. Strauss Center for International Security and Law at the University of Texas at Austin. The project gathers fatality numbers from media outlets and publishes weekly reports. It is the only one consistently counting the number of people killed by Boko Haram.

Analyzed by International Business Times, the data show Boko Haram killed 2,371 people Jan. 1-16. More than 1,700 of those were residents of Baga -- the town where residents were slaughtered by the militant group this month. However, the Nigerian government has claimed only 150 people were killed there.

It is almost impossible for news outlets to grasp the scale of the attack on Baga, as well as other attacks in the region, because of the lack of information. Human Rights Watch published a report saying it had gained access to satellite images of Baga that showed "direct evidence of extensive areas of fire-related damages to local buildings and trees, consistent with a systematic campaign of arson directed against the civilian population in the area."

Boko Haram has infiltrated Baga several times since 2010, but the Nigerian army, along with forces from Chad and Niger, had prevented the militants from taking over completely. This month, those military forces were overrun and abandoned their base in Doro Gowan, leaving thousands in the region to fend for themselves.

IBTimes reached out to aid workers who were serving residents fleeing the northeastern part of the country. Representatives of Doctors Without Borders said its teams were operating out of Maiduguri in Borno state, just south of Baga.

"Our teams are currently unable to reach Baga due to the volatile situation there," said Tim Shenk, a press officer for Doctors Without Borders. "Estimates put the total number of displaced people in the Maiduguri area at 500,000, about 10 percent of whom are in camps set up since July. People in the camps are for the most part villagers who have fled from Boko Haram attacks."

Maiduguri has until now remained the only safe option for humanitarian organizations to set up operation centers. However, Agence France-Presse reported Saturday that Boko Haram militants attacked the town, killing 15 people.

Shenk said residents of the camps in Maiduguri did not come only from Baga, but also from other towns and villages in southern, eastern and northern Borno state.

"In Borno state, there are roughly 500,000 displaced people, of whom roughly 400,000 are in Maiduguri," Shenk said. "Additionally, some people been displaced to Biu town, in southern Borno state, and to areas of Adamawa state."

The U.N. said Jan. 9 that more than 7,000 Nigerians from the northeastern part of the country had fled to western Chad. That number is now likely much higher.

Mia Bloom, an expert on Boko Haram and terrorism at the University of Massachusetts Lowell's Center for Terrorism and Security Studies, said the situation in Nigeria is more complicated than most realize. The violence is fueled largely by tribal tensions and the split between the rural poor and urban elite.

"Everyone reports this as an Islamist-inspired conflict," Bloom said. "But there is a lot more to it. It is not just Islamist versus the secular."

Those tensions are forcing hundreds of thousands of Nigerians to flee to areas of the country, as well as Chad and Cameroon, where they can surround themselves with others from their own tribes. Aid workers in Borno state told IBTimes that thousands are thought to still be living in Boko Haram-controlled territory.

Meanwhile, the United Nations High Commissioner for Refugees has reported that thousands of refugees living in Niger were being transported by authorities back to the northeastern region of Nigeria.

"Given the volatile security situation in Borno state and the recent attacks by insurgents, UNHCR is concerned about the nature of these returns and has asked the authorities to stop this operation until there are proper safeguards and a legal framework between Nigeria, Niger and UNHCR," agency representative William Spindler said in a briefing with journalists Jan. 16.

Nigerians are continuing to flee their homes to seek shelter with humanitarian agencies on the ground. Some of those fleeing have been injured by the violence, and are seeking medical attention. But, as Doctors Without Borders reported, there are only two doctors in the northern part of Borno state.