Tuareg rebels and a militant Islamic sect in Mali say they have joined forces to create an independent, Islamic state in the north.

The new alliance is made up of Tuaregs with the National Movement for the Liberation of Azawad, and members of the al-Qaida-linked extremist group Ansar Dine.

The groups say they signed the agreement late Saturday in the northern town of Gao.

The deal calls for the two sides to join forces in order to create an independent state of Azawad, which is to operate under strict Islamic law, or Sharia.

Mali's transitional government has rejected rebels' claims the north will become an independent state.

The Tuareg rebels and Islamist militants fought side-by-side in a fast-moving offensive to seize the north, following a March 22 military coup in Bamako.

Initially, the Tuareg rebels and Islamist group had separate goals. The Tuaregs sought to create an independent secular state of Azawad, while Ansar Dine wanted to impose Sharia across the entire country.

Sect members have started introducing hardline Islamic law in Gao and Timbuktu.

Residents in the region, who are accustomed to a moderate form of Islam, have resisted the new measures.

Tuareg fighters who worked as mercenaries for Libyan dictator Moammar Gadhafi returned to the country heavily armed. They launched an offensive in northern Mali in January, restarting the latest rebellion in a decades-old struggle for autonomy.