Cairo ( CNN ) -- Egypt 's interim military government Tuesday added two more key figures to its list of Muslim Brotherhood leaders under arrest : Mohamed Badie , the group 's spiritual leader , and Safwat Hegazy , a preacher and hardline supporter of the movement . They were among about 100 members of the Muslim Brotherhood taken into custody Tuesday . The brotherhood -- locked in a deadly battle with the military for control of Egypt -- slammed the interim government 's ongoing `` bloody military coup . '' In a statement , the group 's Freedom and Justice Party described the charges against Badie as `` trumped up '' and `` political . '' `` It is well-known that all the charges brought against the leaders of the Muslim Brotherhood and its affiliated political party , the Freedom and Justice Party ( FJP ) as well as the leaders of the Anti-Coup , Pro-Democracy National Alliance are implausible fabricated charges with no legally acceptable evidence . `` What they are facing are nothing but political trumped up charges thinly painted with criminal colors , '' Ali Kamal , a lawyer for the Muslim Brotherhood , said in the statement . Badie was taken in a dawn raid at a residential apartment in Cairo 's Nasr City neighborhood , the Ministry of Interior said . Arresting Badie `` is not the end of the group , which will remain in the hearts of millions of Egyptians , '' said Ahmed Arif , spokesman for the Muslim Brotherhood . Badie will be detained for 15 days for investigation on accusations of inciting violence and killing protesters , the Ministry of Interior said . The detention could be extended , as has been done with ousted President Mohamed Morsy . Mahmoud Ezzat , Badie 's deputy , was named supreme guide on a temporary basis . Later , Hegazy was arrested in Nasr City as well , according to state-run broadcaster Al-Masriya . Opinion : Can anyone save Egypt from the brink ? The military has been arresting numerous key figures in the Muslim Brotherhood , including Mohamed Mahdi Akef , the former supreme guide ; his deputy , Khairat al-Shater ; Saad al-Katatni , chairman of the Freedom and Justice Party ; his deputy , Rashad al-Bayoumi ; and Sheikh Hazem Salah Abo Ismael . Armed fighters holed up in school facility , military says . Badie was with Syed Abdul Rahim Abdel Naby , a teacher from the Islamic Dawa school in Beni Suef , when he was arrested at dawn , the Ministry of Interior said in its statement . Defterios : Egypt 's cycle of violence threatens to destroy its economy . Security forces then searched the school and arrested 38 members of the Muslim Brotherhood `` who were hiding '' in the facility and had numerous weapons , including a rifle , pistols , and Molotov cocktails , the statement said . Some of the equipment belonged to the administration of the civil protection unit in Beni Suef , which had been stormed , robbed and set on fire , the statement said . Both sides in the conflict have insisted they reject violence , but fighting has raged . The Muslim Brotherhood changed its profile image on Facebook on Tuesday to an image of Badie , with a quote saying , `` Our peaceful movement is mightier than their tanks . '' Nationwide arrests . Security forces also arrested 56 administrative leaders of the Muslim Brotherhood in various provinces , the Ministry of Interior said . The arrests came a day after 25 soldiers were killed in a Sinai ambush and onetime ruler Hosni Mubarak won acquittal on a corruption charge . The soldiers were killed when suspected militants armed with rocket-propelled grenades struck two buses carrying security forces Monday in the city of Rafah , on the border between Egypt and Gaza , Nile TV reported . Interim President Adly Mansour declared three days of national mourning following the attack , Nile TV said . The Sinai Peninsula is a lawless area that was the site of frequent attacks even before Egypt 's latest round of turmoil . In May , for example , seven Egyptian solders were kidnapped and held for six days there , a spokesman for Egypt 's armed forces said . But the attack adds to the persistent tension across the country since the military ousted the democratically elected Morsy in a coup . Over the past week , about 900 people -- security personnel as well as citizens -- have been killed . Deaths occurred when the military used force to clear two pro-Morsy sit-in sites in Cairo on Wednesday and violence raged after pro-Morsy supporters staged demonstrations Friday . Billions in aid on the line : What will the U.S. do about Egypt ? CNN 's Saad Abedin reported from Cairo ; CNN 's Mohammed Tawfeeq , Ali Younes , Schams Elwazer , Ian Lee , Reza Sayah , Hamdi Alkhshali , Slma Shelbayah , and Holly Yan contributed to this report .
NEW : The Muslim Brotherhood describes charges as ` ` made up '' and ` ` political '' Another prominent Muslim Brotherhood leader , Safwat Ali , is arrested . Badie will be detained at least 15 days , Egypt says . About 100 people with the Muslim Brotherhood were arrested Tuesday .