The Islamic Resistance Movement (Hamas) and the Popular Front for the Liberation of Palestine (PFLP) called on Thursday for an immediate forming of a collective leadership in the absence of the ailing Palestinian leader Yasser Arafat.
The two groups issued a joint leaflet after reports circulated that Arafat's health was deteriorating.
The collective leadership must include all Palestinian national and Islamic factions to fill any power vacuum which would emerge after the death of Arafat, the statement said.
The statement came amid fears fed by speculations on a possible death of Arafat that an internal power struggle would emerge in the Palestinian territories since Arafat had appointed no successor yet.
No official Palestinian reports were issued hitherto and the exact conditions of Arafat's health remained a mystery.
Meanwhile, reports from Percy Military Hospital outside Paris where Arafat was admitted were also unclear.
On Thursday afternoon, French medical sources confirmed that Arafat was in a clinical death.
However, Christian Estripeau, a spokesman for the Percy Military Training Hospital, told a news conference in a brief statement that Arafat was still alive.