(Recasts with tunnels, Fatah accusations) Nidal al-Mughrabi GAZA, Jan 15 (Reuters) - Palestinian security forces uncovered an extensive network of tunnels in the Gaza Strip that the Fatah faction said on Monday could have been used to assassinate its top leaders, including President Mahmoud Abbas. The ruling Hamas faction would not say whether it dug the tunnels, discovered by Fatah-dominated security forces in central and northern Gaza on Monday and over the weekend. A Fatah spokesman, Abdel-Hakim Awad, held Hamas responsible but stopped short of accusing the group of being behind any specific assassination plot. Awad said some of the tunnels were lined with explosives and ran directly beneath the homes of prominent Fatah members. One of the tunnels ran underneath the main road leading to the Erez crossing between Gaza and Israel, a key route used by some Palestinian workers into the Jewish state. The crossing and road are also used by Abbas and Mohammad Dahlan, a possible successor to Abbas, and other Fatah officials to reach the West Bank. "This represents ... a premeditated intention to carry out assassination attempts against leaders and symbols of Fatah," Awad said, singling out Abbas and Dahlan. "Any attack on any of our leaders will turn the Palestinian situation into serious chaos and internal fighting, which will spare no one," Awad said. At least 30 Palestinians have been killed in the Gaza Strip since Abbas of Fatah called for fresh elections last month, raising the stakes in his bitter power struggle with the governing Hamas Islamists. GUNMEN Abbas said he would give negotiations over a unity government with Hamas one last chance. But Fatah's accusations about the tunnels could cast a shadow over the renewed talks. Fawzi Barhoum, a Hamas spokesman, declined to comment on the tunnels. "Hamas will not respond to such media provocations ... in order to provide a positive atmosphere to defuse the crisis and to allow the resumption of national dialogue over the formation of a unity government," Barhoum said. Earlier on Monday, Hamas-led policemen arrested six gunmen who stormed into a U.N. office in the Gaza Strip looking for foreigners to kidnap, a spokesman for the force said. The spokesman, Islam Shahwan, said the gunmen, whose identities and affiliations he declined to disclose, had sought to seize international staff at the Khan Younis headquarters of the United Nations Relief and Works Agency (UNRWA). Adnan Abu Hasna, UNRWA's media adviser in Gaza, said no foreigners were present when gunmen, whose number he put at 10, barged in. "We have detained six gunmen ... (and they) are now being interrogated," Shahwan said. Gaza has been hit by a spate of kidnappings in which gunmen attempting to press the Palestinian government for jobs or to free prisoners have seized foreigners, all of whom have been released, usually within hours or days. Recently, some kidnappers in Gaza sought ransoms but it is unclear whether any money was paid.
