( CNN ) -- Five more people are being held in connection with the terrorist attack on the Westgate mall in Nairobi , Kenya , a senior Kenyan government official said Wednesday . The five are in addition to as many as 11 people taken into custody by Kenyan authorities shortly after the September 21 attack . They are scheduled to appear in court on Monday , according to the official , who could not be named due to the sensitivity of the case . Gunmen believed affiliated with the Somalian terror group Al-Shabab stormed the mall at the outset of a four-day standoff that left at least 67 people dead and parts of the center destroyed . Surveillance video obtained by CNN shows gunmen casually shooting some civilians . They reportedly also tortured some hostages , according to military doctors who saw evidence of severed hands and noses . Some hostages had been hanged , according to the doctors . CNN 's Mohammed Tawfeeq contributed to this report .
Five more held in connection with the mall attack , senior Kenyan official says . This is in addition to five others arrested shortly after the September 11 attacks . The suspects are expected to appear in court Monday , the official says .