The recent shoot-out in a Gaza mosque between Hamas security officers and militants from the radical jihadist group the Warriors of God brought to the surface the deep tensions that divide Palestinian Islamists. Twenty-two people died, including the Warriors of God’s leader, Abdel-Latif Moussa. But Palestinian security officials doubt that these will be the last casualties.

With Hamas in control for more than two years, the Gaza Strip has long been considered much more traditional and conservative than the West Bank. Nevertheless, in Gaza’s political milieu, Hamas is a moderate Islamic group that opposes Al-Qaeda-style extremism. But such extremist Islamic groups have been gaining support in Gaza, and Hamas has noticed. The shoot-out in the mosque shows that Hamas will be ruthless in taking them on.

Various Salafist extremist groups have been operating in Gaza for years. Salafists, whose name is derived from the Arabic phrase for “righteous ancestors,” known as “Salaf al-Salih,” insist on a return to what they consider the purity of the practices of the first Muslims.

Hamas has, in the past, cooperated with some of the Salafists, assuming they would stand behind Hamas’ leadership. The Army of Islam joined in the raid that abducted the Israeli soldier Gilad Shalit in June 2006. The group also took responsibility for the 2007 kidnapping of the BBC’s Gaza correspondent Alan Johnston, who was later released after negotiations led by Hamas.

The Warriors of God is one of a handful of radical, Al-Qaeda-inspired groups to have appeared in the Gaza Strip in recent months, first coming to public attention in June after claiming responsibility for a failed horseback attack on Israel from Gaza. Their website shares images, language, and music with Al-Qaeda and other jihadist groups. In a recent declaration, the group made favorable mention of Al-Qaeda leaders Osama bin Laden and Ayman al-Zawahiri.

The Warriors of God group demands a pure form of Islamic practice throughout the Gaza Strip, including the implementation of Sharia religious law and a rejection of democracy. Indeed, the confrontation at the mosque followed the declaration of an Islamic Caliphate in Gaza, a flagrant rejection of Hamas’s authority.

Many young men in Gaza have become increasingly radicalized. Pakistani-style dress has become common, as is the long hair that is thought to resemble the style of the Prophet Mohammad. At the same time, violence against “law-breakers” is on the rise. Internet cafes have been bombed, institutions with Christian affiliations burned down, foreign schools attacked, and wedding parties assaulted.

There are substantial ideological differences between Gaza’s Salafist Al-Qaeda affiliates and Hamas. As a ruling party, Hamas has insisted that its sole concern is the Palestinian people, not a global Islamic revolution. Hamas has not imposed Islamic law in the Gaza Strip.

But the Salafist groups appear increasingly influenced by the growth of Al-Qaeda-style extremism in Pakistan, Iraq, and Afghan-istan. While traditional Salafist movements have stayed away from politics, the younger groups see activism and violence as the best means of realizing their goals.

But Hamas’ failure to establish and implement Islamic law is not the only issue that rankles. One of the reasons for these groups’ increased appeal is the de facto ceasefire between Israel and Hamas, which has led some in Gaza to charge that Hamas has been neutralized as a resistance force. With the border closed under Israeli blockade for more than two years, levels of poverty, unemployment, and despair have grown, with young men increasingly interested in joining the global jihad as it comes to Gaza.

Indeed, Hamas’ confrontation with Salafists comes as Israel is charging that dozens of foreign terrorists have crossed into Gaza from the Sinai to join the violent underground. Hamas’ crackdown thus highlights its desire to maintain control over its conflict with Israel.

The threat of Salafist extremism in Gaza is far from over. Salafists have threatened to retaliate against Hamas, particularly the security brigades that led the counter-attack on the mosque. A new Salafist group called the Brigade of Swords of Righteousness has declared its obedience to the Warriors of God, and has warned Gazans to stay away from government buildings, security headquarters, mosques attended by Hamas leaders, and other official buildings. The group now considers these legitimate targets.

With hundreds of tunnels connecting the Gaza Strip and Sinai, it is very difficult to control the flow of arms, ammunition, and possibly foreign fighters. Hamas’ battle with these radicals, who detonated suicide bombs and killed six Hamas security men during the mosque fight, is just beginning. Residents are afraid that Gaza could become another Iraq, with bombings and mass killings a daily occurrence.

Hamas will use all means necessary to protect its power and to break the jihadist groups now spreading in Gaza. In the process, Hamas hopes to win the international legitimacy that it has long sought.