Palestinian militants opened fire near a children's festival at a UN-operated elementary school in the southern Gaza Strip on Sunday, killing a bodyguard of a local Fatah leader and wounding seven other people, medical officials said. There was no immediate claim of responsibility. But Muslim extremists had earlier visited the school, warning authorities not to hold the festival, UN and security officials said. They also issued a warning on Saturday. It was not clear why the extremists objected to the event, at the school in the southern Gaza Strip town of Rafah, or whether they were behind the shooting, the officials said. The gunmen were masked, making identification difficult, security officials said. At least one foreigner, John Ging, head of the UN Relief and Works Agency in Gaza, was inside the school when the shooting broke out, said Adnan Abu Hasna, spokesman for the agency. Ging was not hurt, but remained holed up inside the school, he said. In March, Ging escaped a kidnapping attempt unharmed after gunmen fired on his convoy. The incident prompted the UN to take stronger security measures, including police convoys for senior staff. Abu Hasna said no UNRWA staff were wounded in Sunday's shooting, which was being investigated. Palestinian medical officials identified the dead man as a bodyguard of Majid Abu Shameleh, a senior official in President Mahmoud Abbas' Fatah movement. Abu Shameleh was leaving the event when the shooting erupted. No children were hurt. Fatah and the Islamic militant group Hamas formed a coalition government in March aimed at ending months of Palestinian infighting. While the sides have largely halted their attacks on each other, Gaza continues to be plagued by clan violence, kidnappings and other crime. The violence has included a string of attacks on Internet cafes, music stores and restaurants by Islamic extremists.