The wedding of Mahmoud Dahlan, the nephew of former PA security chief Muhammad Dahlan, was violently and abruptly ended overnight Tuesday when an explosion caused the stage upon which stood the bride, groom, and other members of the family, to collapse. At least four people were seriously injured in the incident, while 50 others sustained lesser wounds. The wedding took place in Khan Yunis in the Gaza Strip, where a majority of the Dahlan clan is based. Most of those in attendance were affiliated with the Fatah movement, leading some to report that the blast was caused by Hamas. In addition, a Palestinian news agency run by Fatah blamed the Islamic group and reported that guests received calls to leave the party 15 minutes before the explosion. Hamas flatly rejected the claim, and said that its own preliminary investigation found evidence to the contrary. According to Ihabal Ghissin, the Hamas spokesman for the Gaza Ministry of Interior, the probe found that the explosion was a result of a percussion grenade, which cause the stage to give way. Those who were injured were either wounded in the collapse, or by shrapnel. He added that fireworks being used at the wedding might also have played a part in the incident. On Wednesday, a Hamas official said that three people had been detained in connection with the explosion. Muhammad Dahlan and Hamas have been at odds for years. Hamas has blamed Dahlan for a string of misdeeds which were allegedly perpetrated during his reign as security chief in Gaza, while Dahlan has alleged Hamas persecution following his ousting from the Strip in June 2007. Khaled Abu Toameh contributed to this report.