NAIROBI, Kenya — When thundering explosions rattled a small Somali town during a meeting of Islamist insurgent leaders, it sent them scurrying for safety.
An international military appears to have launched the powerful, well-timed attack, but no one will admit it.
The two top possibilities — the U.S. and French militaries — both deny responsibility. Officials from the two countries even suggested it might be the other.
Sunday night's explosion in Afgoye, a heavily populated corridor along a main road leading out of the Somali capital came as Somalia's al Qaeda-linked al-Shabab militia is fighting to defend itself on two fronts.
African Union soldiers have taken over the capital of Mogadishu, and Kenyan soldiers crossed the border into southern Somalia last month.
But neither Kenya nor the AU force — known as AMISOM — was likely to have launched the attack, said Lauren Gelfand, the Africa and Middle East editor of Jane's Defense Weekly.
"To have that kind of strike capability is completely beyond AMISOM. They have no air support," said Mr. Gelfand. "The Kenyan F5s [jets] do have the capability, but whether they have the precision is unlikely."
None of the militant leaders were believed to have been killed.
Kenya's military spokesman said Kenya was not behind the Sunday strike. Kenya has acknowledged other bombing raids in recent weeks.
"The Americans do have the assets required for a targeted strike in the region, as do the French," said Mr. Gelfand. "[The French] have a base in Djibouti from which they launch their tactical support to the European Union's anti-piracy operations."
Both the U.S. and France have motives for launching a missile at al-Shabab's leaders.
The U.S. lists al-Shabab as a terrorist group and previously has killed its leaders or al Qaeda operatives among them with either missile strikes or a special forces helicopter raid.
U.S. officials are alarmed by al-Shabab's recruitment of young Americans. Most, but not all, are the children of Somali immigrants.
Despite the U.S. concerns, a senior U.S. official at the Pentagon denied that America was behind the Afgoye attack. Another U.S. official suggested it was more likely to be France, which also has warships and military assets in the region.
The French are not known to have previously launched missiles into Somalia but have carried out commando raids immediately after the release of French hostages by Somali pirates.
But a French official said France does not have the capability to launch missiles from a drone and that there were no French warships in the area at the time. He said the strike appeared to be a U.S. operation.