JERUSALEM — Islamic Jihad, the militant group responsible for firing dozens of rockets into Israel from the Gaza Strip, announced Thursday that Egypt had intervened to restore calm, offering what at first looked like a familiar resolution to an escalation of violence that had shaken both sides of the border.

But Hamas, the militant Palestinian faction that has ruled Gaza since 2007, said it knew of no such truce, a sign of just how much has changed in recent times in the coastal enclave. Throughout the evening, about a dozen more rockets were launched by smaller cells in Gaza, showing how those changes could affect events on the ground.

Israel responded around midnight by bombing seven more Gaza sites, the military said.

A weakened Hamas has struggled to maintain control since Egypt’s military ousted that nation’s Islamist leaders last summer. Since then, Gaza and its 1.7 million residents have become increasingly isolated and desperate as Egypt shut down hundreds of smuggling tunnels, frequently closed its border crossings and declared Hamas a terror organization. Unemployment is at 39 percent, fuel shortages have led to half-day blackouts, prices for staples are soaring, and travel is thwarted. Hamas has faced mounting challenges from its political rival, Fatah, the Iranian-backed Islamic Jihad, and a host of less organized radical groups.

The upset to the status quo, experts said, may force Israel to rethink its longstanding deterrence strategy, known as cutting the grass, occasional incursions carefully calculated not to create too much chaos.