Mortar shells exploded in the Somali capital, Mogadishu, as regional leaders gathered in the city to discuss their joint offensive against the al-Shabab militant group.
The four shells hit areas near the heavily guarded presidential palace, officials said.
There are no reports of casualties.
The leaders of Kenya, Ethiopia and Djibouti were holding a summit there on Wednesday following recent military gains made by the Somali government against the Islamist militants.
Al-Shabab still controls large areas of Somalia and are continuing to carry out regular attacks.
But they have lost territory since the government, backed by the US and African troops, launched a new offensive last August.
The summit focused on strengthening partnerships in the fight against international terrorism.
Army commanders and defense ministers from the Horn of Africa had earlier held a meeting in Mogadishu, the Somali capital, with the main focus being the ongoing crackdown against the militants who are wreaking havoc in the country and the region.
Chief of Defence Forces Gen Robert Kibochi led the Kenyan team.
The Defense Ministers are from Kenya, Somalia, Ethiopia, Djibouti, Eritrea, and other Troops Contributing nations to Somalia like Uganda and Burundi, who have been integral in the peace-building process in the region.
Somalia has been fighting violent extremism since 2007 when al-Shabaab struck.
The meeting was a pacesetter for the Summit for the heads of state and governments of the frontline nations, which are critical in the fight against al-Shabaab.
For the last couple of months, the Somali National Army has been pursuing the militants from several fronts across Somalia, with the help of US Africa Command, the African Union Transition Mission in Somalia [ATMIS], and local militia, who heeded the call.
Officials have said over 500 al-Shabaab militants have died according to statistics given by the federal government of Somalia, which is also targeting the taxation bases of the militants.
The government has so far closed over 200 bank accounts and 70 mobile phone firms responsible for helping the terrorists do monetary transactions.
Kenya has close to 3,500 soldiers in Somalia while Ethiopia has about 4,500 who control Sectors II and VI respectively mainly in Jubaland which borders the two nations. Al-Shabaab has been targeting the two countries by invading their territories, with the group making attempt to cross over to Ethiopia
The group has been attacking Forward Operating Bases of the soldiers from the two countries and has previously succeeded.
For Kenya, the group raided EI-Adde and Kulbiyow Forward Operating Bases, killing over 100 soldiers.
Ethiopia has also been on the receiving end but her soldiers have managed to contain the militants in Dolow and other neighboring towns.
But the September invasion put the country on high alert according to military experts, forcing the country to declare sections of Jubaland a buffer zone.
