Mogadishu, Somalia - A blast that killed at least 15 people in a Mogadishu stadium where Somalia's transitional prime minister was speaking about plans to bring a government to the lawless country and reconcile rivals has deepened concern over the viability of peace prospects in Somalia, analysts say.

While the cause of Tuesday's explosion is still being debated and Prime Minister Ali Mohamed Gedi was unhurt, its proximity to the premier and the panic it sparked have highlighted uncertainties about restoring a functional government to the anarchic country, they say.

Gedi, whose government was formed in exile, and other Somali officials have insisted the blast was caused by the accidental detonation of a bodyguard's grenade, but diplomats on Wednesday said they had been told it was the result of a failed grenade attack.

Either way, the explosion has underscored the volatile security situation in a capital awash in light and heavy weaponry and controlled by unruly warlords.

"It is very hard to believe that this was an accident ... but it still highlights the risks facing the Somali government," said one East African diplomat, expressing concern that possible future "accidental" explosions could cause more serious damage.

"Whether it was an accident or not, the fact that it happened near the prime minister sends a signal that if such things happen in the future, they might well be called accidents," the diplomat said.

The blast occurred on the fourth day of Gedi's maiden tour of the capital, aimed at building support for his government and ending a bitter dispute over when and where in Somalia it should relocate from exile in Kenya.

While presenting the blast as an accident on Wednesday, shortly after the explosion Gedi called the explosion an "act of violence" that will not dampen his resolve to secure a lasting peace in the war-shattered Horn of Africa nation, which has been without a functioning central government for 14 years.

But an official with the East African Inter-Governmental Authority on Development (Igad), which is soon to send peacekeeping troops to Somalia to assist the government's relocation, said the blast will give people additional pause in supporting the administration.

"There is hesitance in supporting the government," the official said on condition of anonymity. "Right now, there is a total deadlock; the whole peace process would have collapsed were it not for the international community."

Matt Bryden, Somalia analyst for the respected International Crisis Group, said it is unlikely that the blast will seriously affect the peace process, but that combined with other factors it is indicative of myriad problems in restoring stability to the country.

"What we see after a tremendous welcome that Gedi got in Mogadishu is a sense of disappointment arising from things that are happening simultaneously," he said. "There is a sense of lost opportunity."

With the disputes over relocation and the composition of the peacekeeping force still unresolved, Bryden said the peace process is at a standstill.

"This is very worrying," he said. "If the institutions remain divided, this process is at a dead end."

Yet diplomats who were in Somalia at the time of the blast say there appears to be a consensus emerging that it is now time for the militias to go.

"The process of pacification is going on and there is now a consensus among the militias and the ex-militia leaders now in the administration that Somalia should have a central government," said one.

"The era of the warlords is over," the diplomat said, adding that a plan to disarm and canton the militias could be adopted by the government in the coming weeks.

Such a move could ease the deployment of the African Union-authorised Igad peacekeepers who are soon to arrive to try to restore stability for Gedi's government, attempting to succeed in the lawless country where United Nations and United States missions failed miserably in the 1990s.