In Nigeria, the army has been told to investigate alleged abuses of civilians by soldiers fighting a radical Islamist sect in the north-east of the country. Defence Minister Bello Mohammed's move came after a woman was shot dead on Wednesday in clashes between soldiers and suspected members of Boko Haram. Rights groups have accused the army of carrying out other unlawful killings. Fighting around Maiduguri has intensified in recent weeks, causing thousands of people to flee the area.