At least 10 people were killed and nine others were injured on Sunday when gunmen attacked a church and a village market in Adamawa state in northern Nigeria before fleeing across the border to Cameroon.
Four people were killed around the church and six were killed in the market in the Njilan village near the Cameroon border, Reuters quoted Adamawa state police spokesman Muhammad Ibrahim as saying. Nine others were injured and were in the hospital for treatment on Monday.
While the official said the motive for the attack was not known, the area is a stronghold of the Islamist group Boko Haram, which translates as "Western education is sin."
Thousands of people have died in fighting since Boko Haram's insurrection began in 2009.
The actual name of the group is Jama'atul Alhul Sunnah Lidda'wati wal jihad or "People for the propagation of the prophet's teachings and jihad." An Islamic cleric, Mohammad Yusuf, formed the group about a decade ago in Maiduguri city to fight Western education, which he claimed was the reason behind moral and political corruption in the country. Yusuf was from the Salafi movement, which has fueled jihadist terrorism in several parts of the world as a legitimate expression of Islam.
It is believed that Boko Haram gained technical sophistication and weaponry with help from groups like al-Shabaab in southern Somalia and al-Qaida in the Islamic Maghreb in Mali.
The Christian Association of Nigerian-Americans has been lobbying the U.S. Department of State for the designation of Boko Haram as a Foreign Terrorist Organization.
It is believed that Boko Haram is seeking to create an Islamic state in the Muslim-majority northern Nigeria, and violence helps it to make a case for secession from the Christian-majority south. The group, which also targets police and Muslim civilians, has earlier warned that all Christians living in the north should move to the south unless they want to be killed.