Hamas leaders on Sunday stepped up their rhetorical attacks on senior Fatah operative Muhammad Dahlan, holding him responsible for the latest cycle of violence between Fatah and Hamas. Sources close to Dahlan, who headed the Palestinian Authority's Preventive Security Service in the Gaza Strip between 1994 and 2003, denied the charges and accused Hamas of waging an open war against Fatah and its top leaders. The sources expressed deep concern for Dahlan's safety in the wake of the "smear campaign and incitement" waged by Hamas in recent weeks. Hamas has already accused Dahlan of being behind a botched assassination attempt against PA Prime Minister Ismail Haniyeh. On Sunday Hamas gunmen detonated an explosive charge outside the home of Salim Khalil, who is in charge of Dahlan's team of bodyguards, and destroyed the first floor completely. Khalil is currently in Egypt. No one was hurt in the attack. Hamas-run Web sites and spokesmen claimed in recent weeks that Dahlan had set up a special force in the Gaza Strip with the help of the US and Israel to target Hamas representatives. "Dahlan is leading a group of Fatah members who are trying to topple the Hamas government on orders from the Israelis and Americans," said Hamas spokesman Fawzi Barhoum. "The American-Zionist scheme is aimed at eliminating the infrastructure of the Palestinian resistance groups and forcing the Palestinians to make political concessions." The Hamas leaders are convinced that Dahlan deliberately ordered his followers in Fatah to escalate the situation to foil efforts to form a Palestinian unity government. Hamas legislator Mushir al-Masri claimed that Dahlan was acting on orders from Israel and the US to thwart efforts to form such a government. "Dahlan is even acting against the will of President Mahmoud Abbas, who is keen on pursuing the talks with Hamas over the unity government," he said. "Dahlan is known to have threatened Fatah leaders against joining a Hamas-led government." He also accused Dahlan of thwarting a prisoner exchange with Israel that would have seen the release of kidnapped IDF soldier Gilad Shalit, to prevent Hamas from taking credit for freeing Palestinian prisoners. Hamas legislator Yehya Mussa called for bringing Dahlan to trial on charges of perpetrating "crimes" against the Palestinians and serving the interests of Israel and the US. He branded Dahlan as "one of the biggest traitors in the history of Fatah."