Extremists part of group run by leader of Gaza's most-feared clan
The extremist Army of Islam group behind the 16-week-long abduction of BBC journalist Alan Johnston is run by the head of a powerful Gaza clan.
The shadowy group was founded by Mumtaz Dughmush, considered the godfather of one of Gaza's largest, best armed and most feared clans.
Dughmush has at one time or another been allied with the two main rival Palestinian movements - the Fatah party of president Mahmoud Abbas and the Islamist Hamas that overran Fatah in Gaza last month.
In late 2005, he established his own militia, the Army of Islam, thought to be made up nearly exclusively of Dughmush clan members.
The group, one of a myriad of armed outfits in radicalised Gaza, first came to prominence a year ago when together with the armed wing of Hamas and other militants it tunnelled out of Gaza and attacked an Israeli army outpost, killing two soldiers and seizing a third who remains in captivity.
The Dughmush clan were also behind the 2006 kidnapping of two journalists for the US-based Fox News network, security sources say.
The pair were roughed up and forced to convert to Islam during their two-week captivity. Until Mr Johnston's ordeal, they were the longest-held western detainees in Gaza, where hostages have normally been released unharmed within days.
In January 2007, relations between the Dughmushes and Hamas deteriorated when two members of the clan were killed by the Islamists.
The Army of Islam claimed responsibility for abducting Mr Johnston on May 9 - nearly two months after he was snatched off a Gaza City street while driving home from work - demanding the release of Islamic militants, particularly Palestinian-born Abu Qatada, held in Britain.
Following the claim, Hamas said it had cut all ties with the group.
Officially, the Army of Islam speaks the language of radical Islamic groups - it has made demands for the release of Islamic radicals held abroad and has also claimed responsibility for bombing internet and video cafes in Gaza.
'They had a jihadi agenda, not so interested in Israel or Palestine,' Mr Johnston said after being released, calling his captors 'dangerous and unpredictable'.
The Dughmush clan is thought to number between 5,000 and 7,000.