NOUAKCHOTT, Mauritania (AP) — Mauritania called the killing in Mali of 16 preachers from a moderate Muslim sect a "barbaric massacre" and an "odious crime," in comments that underscore heightened tensions between the two neighboring nations.

In a statement, Mauritania’s Minister of Foreign Affairs describes the 16 people who were killed at a checkpoint in the central Malian town of Diabaly as "16 peaceful Muslim preachers" and their killing as "an indescribable criminal act, committed in cold blood without any warning against preachers who were armed with nothing more than their faith."

The preachers, many of whom were Mauritanian, were traveling by road to Bamako to attend a religious conference. Early reports indicate the Malian military mistook them for the Islamic extremists who have seized the country’s north. The preachers were executed on Sunday.