At least four Palestinians were killed and 25 were wounded in clashes between Hamas and Fatah militiamen in different parts of the Gaza Strip on Sunday. The fighting was said to be the worst since the two parties agreed to the formation of a unity government in Mecca in February. Those killed included Suleiman al-Ishi, a senior editor of the new Falasteen daily. Another journalist from the paper, Muhammad Abdo, was seriously wounded. Witnesses said the two were kidnapped by Fatah gunmen near the Ansar area, west of Gaza City, and shot at close range. Sunday's violence began shortly after the assassination of Baha Abu Jarad, a senior commander of Fatah's armed wing, the Aksa Martyrs Brigades, in the northern Gaza Strip. Palestinian Authority security sources said Abu Jarad, who has long been on Israel's list of wanted terrorists, was gunned down by unidentified gunmen as he drove his pickup truck in Beit Lahiya. Tawfik al-Bodi, a bodyguard accompanying Abu Jarad, was also killed in the attack. Nicknamed Al-Saker (The Eagle), Abu Jarad, 34, was also an officer in the PA's Preventive Security Service. In 2004, he escaped an Israeli assassination attempt. Abu Jarad was wanted by Hamas for his involvement in the assassination of Majed Abu Darabiyeh, 40, a senior Hamas official in the Gaza Strip who was gunned down in front of his wife and children late last year. Fatah militiamen and officials accused Hamas of being behind the assassination of Abu Jarad and vowed to avenge his killing. "Hamas is lying about the killing of Abu Jarad," said Fatah spokesman Maher Miqdad. "We reject their attempt to justify the cowardly assassination of our colleague. They want their armed thugs and murderers to continue roaming the streets of the Gaza Strip, pursuing their crimes against Fatah." Khaled al-Masri, a top Fatah official in the Strip, accused Hamas gunmen of shooting at mourners attending Abu Jarad's funeral. He said three children were wounded when members of Hamas's armed wing, Izaddin Kassam, fired automatic rifles at the funeral procession in downtown Beit Lahiya. "Fatah will have to respond very quickly to the massacres perpetrated by the murderers of Hamas," he said. "We call on the interior minister, Hani Kawassmeh, to submit his resignation because of his failure to enforce law and order." Hamas strongly denied that its members had killed the Fatah commander. "Abu Jarad was killed as a result of an internal dispute inside Fatah," said Ayman Taha, a top Hamas official in Gaza City. "Those behind the killing are trying to drive a wedge between Fatah and Hamas. They are also trying to thwart the government's efforts to implement a security plan aimed at ending the state of lawlessness and anarchy in the Gaza Strip." Another senior Hamas official claimed that PA National Security Adviser Muhammad Dahlan and his followers were trying to drag Hamas into another round of violence. The official said that Dahlan, with the help of the US and Israel, was doing his utmost to thwart the unity government's attempts to end the anarchy in the Gaza Strip. The Hamas official claimed that Ishi, the newspaper editor who was killed Sunday, had been "executed" by members of Abbas's Force 17 "Presidential Guard." Hamas also accused Fatah gunmen of kidnapping Dr. Ali Sharif, a prominent Hamas figure and university lecturer. Sharif, 70, was abducted from his home in Gaza City's Sabra neighborhood together with his 20-year-old granddaughter. He was later released unharmed. Sources close to Hamas said Sharif was among 70 Hamas members who were kidnapped by Fatah gunmen in many locations in the Gaza Strip in the past 24 hours. Burhan Hammad, a senior Egyptian intelligence security official posted to the Strip urged Hamas and Fatah to stop fighting and to abide by the Mecca agreement. Abdel Karim Darwish, a prominent businessman, lashed out at both Hamas and Fatah, accusing them of recruiting minors as fighters. He said the two groups were recruiting boys aged 12-18, and taking them out of school. "These children are undergoing military training," he said. "This will have a serious, negative impact on their ability to continue their school studies."