Associated Press is reporting that two people working for the aid group, Médecins Sans Frontières, have been shot in Mogadishu. At least one person is believed to have been killed.
The incident is reportedly related to an internal staffing issue - AP quoted MSF worker Ahmed Ali, who claimed that a recently fired employee was responsible for the shooting.
The news appears to have been broken by @HSMPress, a Twitter account run by Al Shabaab, the Islamist insurgent group:
A fierce battle is now raging inside #MSF office building in #Mogadishu. A gunman has stormed the building & opened fire on MSF staff inside
— HSM Press Office (@HSMPress) December 29, 2011
HSMPress continued to provide updates on the situation as it developed including information regarding the possible identities of the gunman and the victims.