The Somali radical Islamist militant group al-Shabab has issued a high set of demands for the release of a French security advisor it continues to hold captive. The list includes the discontinuation of all French support for the Western-backed Mogadishu government.

The document sent to members of the press demanded that the French end all political and military support to the government, including the use of security advisors.

The Islamic militants also asked for the complete removal of French ships from the Somali coast.

The group additionally listed a few wider stipulations for the release of the Frenchman, calling for the complete withdrawal of all troops operating under the African Union peacekeeping mission in Somalia, known as AMISOM, as well as the exit of all outside security companies.

The statement also includes a vague demand for a prisoner exchange, calling for the release of Islamic militants being held "in countries whose names will be announced later, Allah willing."

Two French security advisors were captured from inside a Mogadishu hotel by opposition fighters in mid-July. The duo was allegedly masquerading as foreign journalists.

Once taken captive, the two men were separated by the Islamic opposition fighters. In August one of the two men escaped to safety.

The al-Shabab statement claims that two were in the war-torn country to collect information in support of AMISOM troops stationed in the country, as well as to help in the training of government soldiers.

When contacted, the French Foreign Ministry refused to comment on the Islamist demands.

But the French Foreign Minister told a French radio station later Thursday that it rejected the terms offered for the release.

The French minister also rebutted the al-Shabab claim that the Mogadishu government was illegal, saying that he had met President Sheikh Sharif Ahmed and his administration represented the legitimate government of Somalia.

The AMISOM headquarters in Mogadishu were hit by two simultaneous suicide bombings mid-Thursday. Two vehicles made it into the compound and then exploded near a petrol tank. Al-Shabab has claimed responsibility for the attack.