Al-Shabab fighters stand in formation with their weapons during military exercises on the outskirts of Mogadishu, Somalia. (Mohamed Sheikh Nor/AP)

It sent photographs of what its says were two government officials, a district officer and a clerk. The photographs came after days of raids into Kenya. Last week, the group killed six people in a raid and took several hostages.

The group has been on Twitter since December, sparking concern in the U.S. government. The New York Times reported, “American officials said they were worried that the Shabab might be using Twitter to reach potential recruits in the West.”

An investigation into the Somali militant network revealed that Somali Americans have taken high operational roles inside the organization, the Associated Press reported.