JERUSALEM (AP) -- Israeli defense officials say that Palestinian militants in the Gaza Strip have for the first time fired an anti-aircraft missile at Israeli aircraft.

The officials say the militants fired the Strela shoulder-fired missile at an Israeli helicopter operating over Gaza last week, but missed their target.

The officials, speaking under condition of anonymity because they were discussing a military operation, said Israeli intelligence has long believed that Gaza militants possessed these weapons, but this was the first time they were fired. They said the air force has taken special precautions for several years assuming the threat existed.

Israel believes the weapons originated in Libya and were smuggled through tunnels along the Egyptian border.

Palestinian militant groups have never acknowledged possessing the weapons.