An image taken on July 13 from a video released by the Nigerian Islamist extremist group Boko Haram shows leader Abubakar Shekau talking about the “Bring Back Our Girls” campaign. (AFP/Getty Images)

It was late Saturday or early Sunday when hundreds of militants descended upon a dust-caked Cameroon town called Kolofata. In remote communities like this, more than 700 miles from the national capital along Nigeria’s border, even the cops fret. “When night falls, we tremble,” one Northern Cameroonian policeman, speaking on the condition of anonymity, recently told Agence France Press. “We don’t sleep.”

Those fears were again confirmed this past weekend night when more than 200 Boko Haram assailants arrived in town. The heavily armed men, witnesses would later tell Voice of America, shot their guns into the air as they went about their grisly business. Witnesses said they pillaged, murdered and kidnapped. In an attack that left at least three villagers dead and the region shaken, the militants captured a local mayor — who’s also a religious leader — and five members of his family. They also surrounded Cameroon’s vice prime minister’s house for nearly an hour, kidnapped his wife and headed back toward the Nigerian border.

“I can confirm that the home of Vice Prime Minister Amadou Ali in Kolofata came under a savage attack from Boko Haram militants,” a Cameroon spokesman told Reuters in a telephone interview. “They unfortunately took away his wife.”

Though disturbing in its own right, the attack appeared neither indiscriminate nor random and underscored Boko Haram’s expanding transnational agenda. In the past several weeks, the militants have allegedly claimed a new town in Northeastern Nigeria and launched raid after raid in northern Cameroon. During that time, two Cameroon shepherds have been allegedly killed. Entire villages, according to AFP, have been razed. And since Friday, Boko Haram has launched three separate attacks in Cameroon, killing at least four soldiers and spurring the Cameroon government to dispatch additional troops to the border.

Although Boko Haram has long attacked on either side of the border, the recent surge in both the number and brazenness of its Cameroon operations signal that Boko Haram, which began as a Nigerian problem, has become a regional one. Its growth, analysts say, shows how a combination of factors including inadequate governmental response, porous, randomly drawn borders and a cross-national ideology can give birth to a regional terrorist movement — a phenomenon unfolding in Syria and Iraq as well.

The emergence of growing Islamic militancies — like Boko Haram — could have profound repercussions if they were to work together, warns Benjamin Eveslage in an article published in Perspectives on Terrorism. “Due to the proximity of some extremist groups in this region and their similar ideology, it is feared that their collaboration would result in the ability to launch globally threatening terrorist attacks,” Eveslage wrote, referring to the fact that many of Africa’s terrorist groups fall within something called the “arc of instability.”

But Boko Haram’s attacks on Cameroon also represent something of a departure from the group’s past, marked largely by domestic assaults that have killed untold thousands. In the first six months of this year alone, Boko Haram has killed at least 2,053 civilians in nearly 100 attacks predominantly in its base of operations in Borno state, according to Human Rights Watch. “Boko Haram is effectively waging war on the people of northeastern Nigeria at a staggering human cost,” explained Corinne Dufka, Human Rights Watch’s West Africa director. “Atrocities committed as part of a widespread attack on civilians are crimes against humanity…”

Historically, the civilians mostly targeted by Boko Haram have lived within Nigeria’s borders, according to an analysis of the group’s rhetoric conducted by Perspectives on Terrorism.  Most of its threats — 83 percent — were directed at domestic subjects, primarily the national government. “Boko Haram has operated similar to a domestic revolutionary group, focusing its violence on security forces with a main goal of overthrowing the establishment for a sharia law-governed state,” analyst Eveslage wrote.

But, he added, there’s the real chance for “a very global ideology.”

The reasons for this push into additional countries are as geographic as they are cultural. Boko Haram’s seat of power is Borno State in northeast Nigeria, where the group’s fighters are believed to be guarding hundreds of captured Nigerian school girls. The only Nigerian state to touch three separate nations, it juts out like a snout into Chad, Niger and Cameroon.

Ethnic and linguistic similarities spill across those borders, which has allowed jihadists to disappear into the greater population. “Boko Haram’s birth in Maiduguri, a city located in the Northeastern corner of Nigeria, bordered by Chad, Niger, and Cameroon, places itself within a predominantly Hausa-speaking population that has linguistic, cultural and ethnic ties to its neighbors,” according to Perspectives on Terrorism, “increasing the risk of conflict spillover.”

Today, it’s difficult to differentiate a Boko Haram militant and a civilian. “The problem is we are fighting and asymmetric battle,” Cameroon Information Minister Issa Tchiroma told Voice of America on Sunday. “Nobody knows who is Boko Haram; they have very much infiltrated here and there [and] it is impossible to know when they will attack.”

In May, the online conversation about Nigeria's kidnapped schoolgirls was all over Twitter. The digital chatter has faded, but Rep. Frederica Wilson (D-Fla.) is determined to get the girls back into the headlines. (Pamela Kirkland/The Washington Post)