US steps up fight against militants

The United States will conduct surveillance and intelligence operations against Boko Haram inside Nigeria, sources familiar with the plan told AFP Friday, a significant escalation of Washington's role in combatting the Islamist group.

The operations will be carried out as part of the recently announced deployment of up to 300 US military personnel to neighboring Cameroon, officials said.

"This is going to be part of our Boko Haram efforts that will be operating throughout the region," one of the sources said on condition of anonymity.

It will not include boots on the ground or offensive combat, but will see US military operations against Boko Haram in Africa's most populous country for the first time.

"It's surveillance and intelligence gathering, not anything offensive," said the same source.

US President Barack Obama on Wednesday announced he would send up to 300 military personnel to Cameroon. Approximately 145 have already arrived in the country.

According to Pentagon officials, the US Department of Defense also has approximately 250 personnel in Niger and 85 in Chad conducting training and surveyance missions.

Nigeria greeted that announcement as a "welcome development."