GAZA CITY, Gaza Strip — Israel claimed a significant blow against Al Qaeda-inspired militants in the Gaza Strip on Sunday, killing one of the most influential leaders from an extreme branch of Islam that has targeted Egypt and Gaza’s Hamas rulers as well as Israel.
Hisham Saidani was killed alongside another top militant in the northern Gaza Strip in an air strike late Saturday, Israel’s military said. He was one of the main ideological guides for the violent, ultra-conservative Islamic movements in Gaza known as Salafi jihadis.
The Israeli military said Saidani, 43, was suspected of carrying out attacks against Egyptian and Israeli targets, but they would not provide further information.
Militants on jihadi websites identified the other dead man as Ashraf Sabah, 37. They said he was the leader of another Al Qaeda-inspired group, Ansar al-Sunnah.
Saidani led a small group, ‘‘Tawhid wal Jihad,’’ or ‘‘Monotheism and Holy War,’’ believed responsible for killing an Israeli civilian working along the Egyptian border last June. He was linked to the Mujahideen Shura Council, another militant group in Gaza and Egypt’s neighboring Sinai Desert.
Salafi militants emerged in Gaza around 2005, after Israel withdrew from the territory. Members of one such group, the Army of Islam, cooperated with Hamas in the abduction of an Israeli soldier the following year. But after Hamas seized power in Gaza in 2007, the sides parted ways.
Several hundred Salafi militants are now believed to be in Gaza. Saidani was the best known.
Saidani returned to Gaza in 2008 when Gaza militants blew a hole through the border fence with Egypt. Thousands of people crossed the border at the time.
Saidani followers were responsible for kidnapping and killing Italian activist Vittorio Arrigoni in Gaza last year. Saidani later denounced the act.
He sought to unite the many groups of ultraconservative Salafis in Gaza, according to jihadis commenting about his death.
In response to Saidani’s death, Al Qaeda’s media arm warned Israel that its ‘‘joy will not last long.’’
‘‘We fully trust our brothers that they will be capable of avenging the killing,’’ said a statement by the Global Islamic Media Front, a European group that supports Al Qaeda and other extremist organizations.
Over the past year, Israel has targeted militant Salafi militants with airstrikes in Gaza, seeing them as a new threat to its southern border.
On Sunday, Israeli airstrikes killed three more militants, said Palestinian health spokesman Ashraf al-Kidra. In all, five militants were killed in weekend fighting.
Israeli officials believe the militant Salafis sometimes cross between Gaza and Sinai, using the lawless Egyptian territory as a base to conduct attacks or to flee after carrying out attacks elsewhere.
They are considered a threat not only to Israel, but to Hamas and Egypt as well.
Militant Salafis consider Hamas, which itself is dedicated to Israel’s destruction, to be too moderate because it seeks to establish a Palestinian state.