Former Palestinian premier Mahmud Abbas urged Palestinian forces to unite, pledging loyalty to Yasser Arafat, as he moved to the political centre stage with the strongman sick in hospital. Abbas spoke after chairing the first Palestine Liberation Organisation executive meeting without Arafat, amid speculation that the Palestinian leadership could fall into chaos should the veteran leader never return. "We call on all our people and factions to unite and work together in responsible fashion to protect our destiny and homeland," said Abbas, who is standing in as PLO chairman while Arafat is treated for a mystery disease. Initial tests at a top Paris military hospital have ruled out leukaemia, said Palestinian representative in France, Leila Shahid. "For the moment, the doctors have excluded any trace of leukaemia," she said outside the hospital. "We can say his general condition ... is much better both physically and psychologically." Hosni al-Aatari, head of the hospital in the West Bank city of Ramallah, where Arafat was barricaded in his headquarters by the Israeli military for three years, backed up the findings. "If it had been leukaemia, we would have known from the first day because leukaemia is easy to diagnose. The decision to send Arafat to France was taken in order to test for different kinds of blood disorders other than cancer." He also said tests had been run to see if Arafat was poisoned. "We looked for that but we didn't discover anything, but if it was a rare poison, it is possible the doctors in Paris could identify that." "We were told to wait for the next 48 hours by the French doctors and not to jump to any conclusions and they will give us a full report when they finish the tests," Palestinian negotiations minister Saeb Erakat told CNN. The French defence ministry said doctors have banned any visitors from seeing the weakened veteran leader for the next few days. It is the first time in almost three years that Arafat, who has become a symbol of the Palestinian struggle for statehood, has been allowed to leave his Ramallah base, a sign of the gravity of his condition. Back in the West Bank, Abbas, who resigned as premier in September 2003 after a series of confrontations with Arafat, hoped that the 75-year-old leader "would soon return to his people and his cause who very much still need him". He said the PLO executive committee would hold regular meetings with all Palestinian factions, to guarantee national unity and that contact would be maintained with Arafat. "He (Abbas) is the most senior official now after Yasser Arafat because he is the general secretary of the executive committee of the PLO," prominent Palestinian deputy Hanan Ashrawi said of Abbas. Symbolically, the iconic leader's chair was left empty at the PLO meeting. Abbas sat to the right, with current Prime Minister Ahmed Qorei, who is handling the day-to-day affairs of the Palestinian Authority, to the left. Ziad Amr, a former minister under Abbas, expressed doubt that the PLO would be able to prevent a "constitutional void" in Arafat's absence. Meanwhile, Palestinian schoolboy Brahim Kamel was killed when Israeli soldiers shot him in the neck in the northern town of Jenin, where Palestinian security sources said the army has been waging a four-day operation. His death raised the overall toll since the September 2000 start of the Palestinian intifada to 4,539 people killed, including 3,508 Palestinians and 957 Israelis, according to an AFP count. An army spokesman said Israeli units had come under attack from hundreds of demonstrators throwing stones and Molotov cocktails in part of the town. Two other Palestinians -- one in a critical condition -- were hospitalized with gunshot wounds in the southern Gaza Strip, hospital sources said. An Israeli military source said troops had opened fire on four suspects east of Gaza City and two were hit. **PHOTO CAPTION*** Palestinian leader Yasser Arafat's empty chair is seen as Palestine Liberation Organisation (PLO) Secretary-General Mahmud Abbas (L) and Prime Minister Ahmed Qorei (R) chair the PLO executive committee meeting in Ramallah. (AFP)