At least 19 people were killed in Maiduguri on Saturday and four in Potiskum on Sunday, January 11, 2015.

The Islamist Boko Haram group in Nigeria has diversified its strategy and method of operation from armed attacks to suicide bombings with female suicide bombers as the main perpetrators of their heinous acts.

On Saturday, January 10, 2015 in the Borno State capital, Maiduguri, a  girl of about 10 years old  using a bomb strapped on her,  killed at least 19 people  and injured several others as the bomb exploded in a market, BBC reported citing Police sources. The following day, Sunday, January 11, 2015, two female suicide bombers struck a crowded market in the city of Potiskum in Yobe State, killing at least four people and injuring dozens. No group has so far said it carried out the Maiduguri and Potiskum suicide bomb killings but all signs point to the militant group Boko Haram.

Gideon Jubrin, Borno State police spokesman said the girl bomber in Maiduguri let off an improvised explosive device near the area of the Maiduguri market where chickens were sold.

The BBC reported an eyewitness in the Potiskum bombing who said the second bomb went off shortly after the first, hitting those helping victims of the first bomb blast. "The second bomber was terrified by the explosion and she tried to dash across the road but she also exploded," BBC said, quoting a security official.

Two people are also reported to have died in Yobe State on January 10, 2015 when a vehicle exploded at a checkpoint near a Police Station. Reports say the blast followed heavy fighting in the State capital, Damaturu on January 9 night, with buildings destroyed and civilian casualties reported.