The militant group Boko Haram's latest attack in Nigeria has once again put the spotlight on the violence erupting in the African country.

International watchdogs fear an attack last week in the town of Baga could be the deadliest strike yet, but the actual death toll remains unclear. The Nigerian government, which experts say has a history of underplaying the level of violence, insists no more than 150 people died. Experts and outside agencies quote witnesses saying closer to 2,000 people were massacred.

Here's a recap of the conflict in Nigeria.

What Is Boko Haram?

Boko Haram is a militant Islamic group that has existed for more than a decade in Nigeria, but it has become increasingly violent since an internal leadership change in 2009.

Prior to clashes with police in 2009 over the group's refusal to follow a motorcycle helmet law, the group was not intent on violently overthrowing the government, according to the Council on Foreign Relations.

During those clashes, the group's then-leader Mohammed Yusuf was executed on live television and the group then splintered before becoming significantly more violent.

The group's targets have expanded and its violent attacks have become more frequent, according to John Campbell, who served as the American ambassador in Nigeria from 2004 to 2007 and now works as a senior fellow at the Council on Foreign Relations. Government officials, police and military forces are among its most regular targets, but according to the Council on Foreign Relations, it has attacked a United Nations building as well as multiple religious and public institutions.

The disturbing trend of killing or kidnapping civilians -- including young school children -- has happened frequently since 2011 and the practice came under international scrutiny when there were reports in mid-April 2014 that the group kidnapped more than 270 schoolgirls and threatened to marry them off to jihadis or sell them as sex slaves.

The group has stated that it believes the government is corrupt and feels that the country, which has large Christian and Muslim populations, should be ruled under strict Islamic law.

(ABC News)