A Palestinian Islamic group confirmed on Tuesday that its "armed wing" is targeting what it called "Christian missionary activity" in the Gaza Strip.

In a statement faxed to WorldNetDaily, the Islamic outreach Jihadia Salafiya admitted that gunmen affiliated with the group had carried out a deadly attack on a UN-run school in Gaza on Monday.

One person was killed and six others were wounded when the attackers hurled grenades at the school, after declaring over loudspeakers that the institution was "corrupting Islam" by allowing boys and girls to participate together in sporting activities.

In its official statement, Jihadia Salafiya accused the UN of "spreading Christian missionary activity" and "trying to convert our Muslims under the cover of an international organization."

The group said it "will keep hitting them and trying to kill them."

Last month, the head of Jihadia Salafiya, Abu Saqer, praised other Muslim elements for bombing a Christian bookstore in Gaza.

The Bible Society bookstore, which was funded by American Protestants, was severely damaged in the blast.

Research over the past decade has shown a systematic campaign of persecution against Palestinian Christians by the Muslim majority.

However, most Christians in Judea, Samaria and the Gaza Strip are too afraid to speak out themselves, and have instead opted to leave the region.