Amid reports of clashes between rival factions of Naga rebels, the government will hold talks with the top leadership of the National Socialist Council of Nagalim (Isak-Muivah) in Amsterdam for three days beginning Tuesday where the group may toughten its stand on unification of Naga-inhabited areas.

A Group of Ministers, headed by Union Minister Oscar Fernandes, has left for the Netherlands to hold parleys with NSCN (I-M) representatives led by chairman Isaac Chisi Swu and general secretary Thuingaleng Muivah and is expected to discuss all "substantive" issues for a solution to the country's oldest insurgency problem, sources said on Monday.

The reports of clashes between NSCN (I-M) and its rival NSCN (Khaplang) cadres, which have resulted in killing of several people in the recent past, may figure in the talks.

The NSCN (I-M) is likely to demand immediate government action to "control" the cadre of NSCN (K), which also has a ceasefire pact with the Centre, since such incidents may increase further tension in Nagaland, sources said.

The meeting will review the progress made ever since the rebels submitted a 20-point "Charter of Demands" to the government.

In its "charter of demands", the NSCN (I-M) has sought unification of all Naga-inhabited areas of the northeast, separate representation at the UN and greater rights over natural resources, finance, defence and policing.

The Naga side is expected to insist on commitment from the Centre to its key demand of unification of Naga-inhabited areas to please its constituencies in Nagaland, sources said.

However, the rebel group's key demand of 'Greater Nagalim' has been strongly opposed by Nagaland's neighbouring states -- Manipur, Arunachal Pradesh and Assam.