Jerusalem — The Gaza Strip's Hamas rulers have obtained antiaircraft missiles, Israel's prime minister said Monday, in a potentially game-changing development that could threaten the Israeli air force's ability to strike at the Islamic militant group.

Israeli aircraft have long dominated the skies over Gaza, striking suspected Hamas military installations and assassinating dozens of wanted militants. The Israeli air force played a key role in a fierce three-week Gaza offensive in the winter of 2008-09, which began with airstrikes that killed hundreds of Hamas fighters.

Speaking to his Likud party, Prime Minister Benjamin Netanyahu said that Israel's aerial dominance had been compromised by the weaponry presumably smuggled into Gaza through tunnels connected to neighboring Egypt. He said any future peace agreement would have to include security arrangements to deal with the threat.

Netanyahu's assessment was the first time an Israeli official has openly said Hamas possesses antiaircraft weaponry, though intelligence officials have said privately they suspected that was the case.

The Israeli leader gave no evidence to support his claim, and Hamas accused him of spreading propaganda to justify future attacks in Gaza.