Hamas has resumed its policy of shaving mustaches of political opponents to humiliate them, Fatah officials said Wednesday. Hamas resorted to this form of punishment in the past after arresting senior Fatah representatives in the Gaza Strip, the officials said. Hamas, for its part, accused the Palestinian Authority security forces of shaving the beards of detained Hamas officials in the West Bank. The latest victim of the mustache-shaving policy is Nafez al-Namnam, a top Fatah operative in the Strip. Namnam, 51, is one of the commanders of Fatah's armed wing, the Aksa Martyrs Brigades, in Gaza City. He and his son Rami were arrested by Hamas policemen shortly after the mysterious explosion that killed five Hamas men on the beach in Gaza City last Friday. The father and son were among more than 150 Fatah members who were rounded up by Hamas in the aftermath of the bombing. Namnam wore an unusually large mustache for more than 30 years. But while in prison, his Hamas interrogators shaved it off before finally releasing him. The Aksa Martyrs Brigades issued a statement strongly condemning the shaving of Namnam's mustache and threatening retaliation. It said that Namnam and his son were also tortured while in detention. Earlier this year, another senior Fatah official, Ibrahim Abu al-Naja, also lost his mustache in the power struggle with Hamas. Fatah officials held Hamas responsible, saying the act was designed to humiliate Abu al-Naja, who is one of the most senior leaders of Fatah in the Gaza Strip. Hamas, however, said Abu al-Naja's kidnappers were former Fatah security officers who were angry because the PA had not paid them their salaries. Abu al-Naja had worn a mustache for nearly 35 years.