Afghanistan, Aug. 11 -- An Afghan man has been arrested in Houston over the killing of a former U.S. military interpreter, who was also a well-known advocate for Afghan refugees.

Authorities in Houston have arrested an Afghan national in the fatal stabbing of Abdul Rahman Niazi, a former U.S. military interpreter and prominent advocate for Afghan refugees.

According to a Harris County court affidavit cited by NBC News, the suspect, Masihullah Sahel, allegedly attacked Niazi after repeated arguments, stabbing him more than 20 times.

Niazi's body was discovered in his office, where investigators reported clear signs of a violent struggle. Police have not disclosed a motive for the killing.

Sahel was initially granted release on a $750,000...