"Until we get the Islamic state, we will continue with the Islamic struggle in Somalia," Sheikh Sharif Ahmed, chairman of Mogadishu Islamic courts, told a rally of hundreds of people on Tuesday
Fuad Ahmed, a militiaman loyal to the Islamist side, said: "This is a long Islamic struggle and it will continue until the whole country comes under Sharia [Islamic] law.
"We are ready to shed our blood in order for that struggle to succeed."
Fighters loyal to Islamic courts seized the capital on Monday from a coalition of warlords, the so-called Alliance of the Restoration of Peace and Counter-Terrorism (ARPCT), which many observers say receives financial support from Washington. The US regards Somalia as a haven for militants linked to al-Qaeda.
The US has yet to react to the militia's call for an Islamic state, but Sean McCormack, the state department spokesman, said on Monday: "We do have real concerns about the presence of foreign terrorists in Somalia, and that informs an important aspect of our policy with regard to Somalia."
"Until we get the Islamic state, we will continue with the Islamic struggle in Somalia"
Sharif Ahmed, chairman of
Mogadishu Islamic courts
But an analyst with Chatham House, a British think-tank, said the establishment of an Islamic state in Somalia was not necessarily bad news.
Alex Vines, who heads its Africa Programme, said: "If it it has a unifying effect and brings back stability to the country, an Islamic state is in itself is not a threat.
"The lack of stability, the armed chaos and the absence of coherent control over the country is a bigger threat."
Somalia's interim prime minister, Mohamed Ali Gedi, congratulated the Islamic side on its victory over the warlords, who many Somalis believe tried to undermine the government.
"They were hurting reconciliation, stabilisation and pacification of Somalia," he said. "All those forces who joined their efforts together were the pillars of the victory and the government has congratulated them."
The ARPCT warlords have vowed
to recapture lost ground
As to whether the Islamists could bring the war-torn country back to its feet, Vines said: "There is some potential, if only because there is tremendous fatigue with the violence at the grassroots level.
"But it's far too soon to say if the Islamists' claim they have seized Mogadishu is not exaggerated. How unified are they?"
Somalia is socially organised through a network of clans and sub-clans that can have shifting alliances.
Vines also said: "Washington is watching very carefully and I hope there won't be knee-jerk reaction."
Warlords refuse defeat
Also on Tuesday, defeated warlords said they would fight back and clan elders warned the Islamists against more advances.
Supporters of the warlord coalition held a rally in what remains of Benadir stadium in the north of the capital.
Bashir Raghe, a warlord who lost control of an airstrip and a port in March, said: "We have to continue fighting the terrorists in Mogadishu. We will remain in Mogadishu. The Islamic courts cannot dislodge us from here."
The Islamists advanced towards the warlord stronghold of Jowhar, about 90km north of the capital, on Tuesday.
Siyad Mohammed, a militia leader allied to the Islamic courts, said: "Our forces are in the village of Qalimoy, 20 kilometres south of Jowhar. We are just waiting for orders from our leaders to capture it."
Ali Nur, a warlord coalition militiaman, said clan elders had threatened to mass militia against the Islamic forces if they attacked Jowhar.
Nur said the Islamic side told the warlords to hand over weapons but their fighters were preparing an assault to regain lost strongholds in Mogadishu strongholds, notably the Kilometre Four area.
"If it it has a unifying effect and brings back stability to the country, an Islamic state is in itself is not a threat"
Alex Vines, head of the Africa Programme at the Chatham House think-tank
"We are preparing ourselves to repossess our territory. ... We have close to 100 technicals," he said referring to pick-up trucks mounted with heavy guns.
'Peace is in the air'
But a resident in Kilometre Four said checkpoints set up across Mogadishu had come down.
Fahran Gure said: "The coalition forces have moved closer to Kilometre Four but I don't think they will clash with the Islamic courts militia because elders have intervened.
"We feel there is a big change, peace is in the air, no gunshots can be heard. It is calm, businesses are fully operational. People are now moving freely everywhere."