CAIRO — Egypt has determined that Hamas and its Palestinian allies established rocket launch sites in the northeastern section of the Sinai Peninsula. Egyptian security sources said Hamas and Palestinian militias in the Gaza Strip have developed an underground infrastructure of rockets and tunnels in northeastern Sinai.

The sources said the infrastructure was meant to sustain attacks on Israel amid a major ground invasion by Israel. “There have been major changes to how Hamas and Islamic Jihad operate over the last year,” a source said.

The sources said Hamas and Jihad cooperated in establishing rocket workshops in Sinai. They said the Palestinians, with help from Bedouin smugglers and insurgents, transferred equipment from the Gaza Strip to Rafah and surrounding villages in the northeastern part of the peninsula.

On Aug. 21, Egypt’s official Middle East News Agency reported an army operation on Rafah and the nearby town of Sheik Zweid, both along the Sinai border with the Gaza Strip. MENA said four unidentified insurgents were killed and two others injured in a crackdown on suspected rocket sites.

“Thirty-one huts and houses used as launching pads for rockets were destroyed in the crackdown,” MENA quoted an Egyptian security source as saying. The sources said Sheik Zweid has become a stronghold of Hamas and Jihad rocket operations. They said the two forces also transferred smuggling and operations tunnels from Rafah to Sheik Zweid, regarded as a base for Al Qaida-aligned militias in Sinai.

The Egyptian military has reported the destruction of 90 percent of the estimated 1,200 Palestinian tunnels that connected Sinai and the Gaza Strip, most of them along the divided town of Rafah. But the sources acknowledged that Hamas and Jihad built scores of tunnels that moved north to Sheik Zweid.

“The army has gained full control of Rafah, but faces much greater resistance in Sheik Zweid,” the source sai