Nearly two weeks after Yemeni President Ali Abdullah Saleh sought surgery in Saudi Arabia after suffering severe wounds during an attack on his presidential palace, Yemeni authorities still haven't determined who was responsible for the assassination attempt, though they've announced the arrests of several unnamed suspects this week and even brought in an FBI forensics team to help with the investigation. The issue, it seems, is that Saleh has a lot of enemies, including--but not limited to--anti-government protesters throughout the country, Islamic militants in the south, and Yemen's official opposition parties, renegade military units, and rival tribal fighters in the capital, Sanaa. Who was behind the palace attack? Here's the evidence for the leading suspects:

• Inner Circle: Evidence from the scene, Sarah Phillips notes at Foreign Policy, suggests that the explosion was caused not by a mortar shell or rocket, as initially reported, but by a device placed inside the palace's mosque where Saleh was praying. "If true," she adds, "this means that someone with close access to the president was involved." Phillips examines why the political settlement that held Saleh's inner circle of 50 or so relatives and members of his Sanhan tribe together for three decades may be collapsing, pointing to Gen. Ali Mohsen al-Ahmar decision to defect from the Saleh regime in March as the "first spectacular rupture within the group." Similarly, U.S. analysts at STRATFOR who evaluated photographs of the blast site concluded that the attack was an "inside job." Whoever placed the explosive device, the analysts add, "knew Saleh's routine" and "knew the compound." 
• Official Opposition: Yemen's state-run Al Methaq newspaper reported on Monday that its interrogation of suspects had revealed "important, grave" facts "related to Al Mushtarak--a reference to the Joint Meetings coalition of opposition parties who are demanding that Saleh relinquish power, according to Al Arabiya. When the attack first occurred, the authorities pointed fingers at tribesmen loyal to the Ahmar family, whom Yemeni security forces had been battling for weeks.
• Al-Qaeda: American involvement in the investigation suggests that the Yemen-based al-Qaeda affiliate al-Qaeda in the Arabian Peninsula, which the U.S. is covertly attacking in the south, may have been behind the attack, according to The Yemen Times. "The Yemeni government has said that it believes al-Qaeda was behind the attack," Yemeni political analyst Abdul Ghani Al-Iryani told the paper. "And it is quite possible."

In Saudi Arabia, meanwhile, a Yemeni official reported that Saleh has developed a throat problem but is stable after his surgery. Things are less stable back in Yemen, where a bomb today killed a military officer loyal to Saleh near the southern port of Aden. It's not clear who was behind the attack.

Want to add to this story? Let us know in comments or send an email to the author at ufriedman at theatlantic dot com. You can share ideas for stories on the Open Wire.
Uri Friedman