June 21 (Reuters) - The United States on Thursday put three alleged leaders of the Nigerian militant Islamist group Boko Haram on its list of "foreign terrorists" for the first time.
Here is a look at Boko Haram:
* Boko Haram became active in 2003 and carried out its first attack in 2004. It has its heartland in the far northeastern corner of Nigeria around Maiduguri.
* In the Hausa language, Boko Haram means "Western education is sinful." It is loosely modelled on the Afghan Taliban and its followers wear long beards and red or black headscarves.
* It demands the adoption of sharia (Islamic law) across Nigeria and considers all who do not follow its ideology as infidels, whether Muslim or Christian.
* In a YouTube video posted in April, purported leader Abubakar Shekau said he aimed to "devour" President Goodluck Jonathan and bring down the government within three months.
* The United States on Thursday has applied the "terrorist" designation to three men presumed to be central figures in the group. The three are Abubakar Shekau, described as a Boko Haram leader who allegedly aligned himself with al Qaeda; Abubakar Adam Kambar and Khalid al Barnawi.
* Former sect leader Mohammed Yusuf was shot dead in police custody in 2009 after about 800 people were killed in fighting between security forces and Boko Haram.
* In its most lethal attack, at least 186 people died in Kano in January 2012 in coordinated bombings and shootings. A bombing at the U.N. building in Abuja killed 23 people in August 2011.
* Boko Haram has killed hundreds in gun and bomb attacks in 2012. Human Rights Watch said in January that the sect had killed at least 935 people since 2009.
* Boko Haram has repeatedly struck churches during services, carrying out attacks at Christmas and Easter which killed scores of people.
* Gunmen killed at least 19 people in two attacks on Christian worshippers in the Nigerian city of Kano and in the northeastern town of Maiduguri on April 29 and killed the suspected mastermind two days later in Kano.
* A May 2 attack by gunmen killed at least 56 people in the town of Potiskum, in Yobe state, which has been an occasional target for the militant Islamist sect. Police have confirmed 34 dead and that Boko Haram was suspected to be behind the attack.
* A suicide bomber drove a car full of explosives into a church in in Yelwa, on the outskirts of Bauchi on June 3.
* June 10 - Three gunmen spray bullets at the congregation of a church in Biu Town, in northeastern Borno state. In Jos, suicide bomber drives car to the entrance of the Christ Chosen Church and blows it up, witnesses say. Youths attack bystanders in retaliation, killing two, police say. Boko Haram claimed both attacks. Sources: Reuters/Janes World Insurgency and Terrorism, 2012 (For full Reuters Africa coverage and to have your say on the top issues, visit: http://africa.reuters.com/) (Reporting by David Cutler, London Editorial Reference Unit)