A representative for the U.S. State Department said last week that Washington was "deeply concerned" about reports of violence in northern Mali. Washington late last year issued a travel advisory out of concern that al-Qaida was plotting against Western targets in the region.
Fighting in Mali attributed to Tuareg rebels erupted in January when they returned from fighting alongside forces loyal to former Libyan leader Moammar Gadhafi. The simmering conflict, after years of peace, rekindled ethnic tensions between northern and southern Malians.
Pierre Verbeeren, director general of Doctors Without Borders, said from Belgium the agency had to halt operations because of the security situation in Mali.
"The conflict makes the situation very insecure for our teams and the population," he told the BBC. "The population is leaving so it is very difficult for us to reach them, so we decided to suspended temporarily the activities to deliver primary health care, medicine and sometimes food."
Last week, Malian President Amadou Toure called for calm as ethnic tensions simmer in the West African country.