JIHADISTS IN GAZA AGAINST CO-ED SPORTS

Here, it was at a UN-based facility that they attacked:

Palestinian gunmen opened fire at a sports day at a United Nations-operated elementary school in the southern Gaza Strip on Sunday, killing a bodyguard of a local Fatah leader and wounding seven people. Although no one has yet claimed credit for the attack, Muslim extremists had earlier visited the al-Amareya school in Rafah, warning authorities not to hold the event, because boys and girls were taking part together. The gunmen said the event "taught children immoral values."

Previous violence in Gaza has included a string of attacks on Internet cafes, music stores and restaurants by Islamic extremists.

Something tells me that given the chance, they'd object to sports altogether as it represents entertainment, just like a party.