Two Gaza militants killed by Israel on Saturday were the most senior al-Qaeda affiliates in the Palestinian enclave, and one had links to jihadi networks in Egypt, Jordan and Iraq, sources said on Sunday.
Hisham al-Saedni and Ashraf al-Sabah, who were killed by an air strike as they rode a motorcycle, were ultra-conservative Salafi Islamists.
Armed Salafis, while a fringe presence in Gaza, have been stepping up violence against Israel while at times clashing with the Palestinian Hamas government. They also operate in the neighbouring Egyptian Sinai.
Saedni and Sabah were leaders, respectively, of the Tawhid wa-Jihad and Ansar Al-Sunna groups, two Salafi sources said. The movements share al-Qaeda's vision of global jihad and opposed the more pragmatic Islamism espoused by Hamas and Cairo's politically dominant Muslim Brotherhood.
The men had recently merged their groups to form the umbrella Majles Shoura Al-Mujahideen (Holy Warriors' Guidance Council), the sources said, becoming the de facto heads of the diffuse Gaza jihadi network.
"Their blood will be a light to guide the holy warriors through the right path and will be fire that will burn the Jews," one of the sources told Reuters, saying reprisals would not be limited to the short-range rocket launches that are Gaza militants' favoured mode of attack on Israel.
The Salafi sources said Gaza-born Saedni, 47, had lived in Egypt and Jordan and had fought for al Qaeda in Iraq. He had been wanted by Egypt on suspicion of involvement in attacks on tourist sites there.
Israel said the militant, who was freed from a Hamas jail in August after 11 months' locked up, had been behind a string of rocket and bomb attacks against the country and had planned to carry out a militant operation on its Sinai border.
"The Global Jihad is stepping up its efforts to target us, and we will continue to interdict it with aggression and might, in terms of both response and pre-emption," Prime Minister Benjamin Netanyahu told the Israeli cabinet in Jerusalem on Sunday.
In a sign of Salafi assertiveness in Gaza, about 500 mourners attended Saedni's and Sabah's funerals on Sunday. Some wore the smocks typical of the al Qaeda bastions in Pakistan and Afghanistan but relatively uncommon among Palestinians.
Jihadi gunmen have raided Israel through the Sinai, a desert peninsula which has seen a surge of lawlessness during the political upheaval that has rocked Cairo since early 2011 including an Aug. 5 massacre of Egyptian border policemen that drew an unprecedented Egyptian security sweep.
On Sunday, a separate Israeli air strike killed a Palestinian gunman and wounded another in southern Gaza, near the Sinai border. The military said the men - also targeted while on a motorcycle - had been planning to fire rockets into Israel.
In another incident, a rocket landed in Israeli territory but caused no damage, a military spokeswoman said.