Hamas said Saturday its fighters will keep targeting Israeli aircraft with heavy machine guns, after hitting an Israeli helicopter over Gaza for the first time.

The Israeli military did not comment on Friday's incident, but security officials said the helicopter was lightly damaged and returned to Israel safely.

It was not immediately clear whether Friday's hit was an isolated incident or a sign of Hamas' increasing military capabilities. Hamas is believed to have more than a dozen Russian-made KPV-14.5 machine guns.

A Hamas video on YouTube showed a Hamas fighter aiming a machine gun toward the sky as a helicopter flew above. Another Hamas man stood under green tarp used as a visual shield from aircraft. The text accompanying the video said Hamas has also used the machine guns against Israeli armored personnel carriers.

Abu Obeida, spokesman of the Hamas military wing, said that in Friday's incident, Hamas fighters fired at an Apache helicopter with machine guns from several directions.

"This is progress for the resistance," Abu Obeida said. "It's a message to the occupation that our resistance men will confront the Zionist war planes, vehicles and soldiers with any means they get."

Israeli officials have said Hamas is developing a weapons industry in Gaza, using the smuggling routes through Egypt to upgrade its fighting capabilities and to improve the range of its rockets to hit deeper inside Israel.

Hamas militants say they are trying to improve their arsenal, but insist their weapons are largely homemade, and deny smuggling technology from Iran.

Abu Obeida said the machine guns were confiscated from security headquarters of its rival Fatah last year. Hamas militants overran Fatah security forces in a violent showdown last summer, seizing security posts and most of the Fatah-controlled arsenal since.

Some security officials estimate that Hamas has at least 14 Russian-made machine guns, and has set up an "anti-aircraft unit" to use them.

"We took them. We fixed them and we are using them now to defend our people," Abu Obeida said.