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GAZA, Jan 29 (Reuters) - Israeli warplanes bombed an open area in the southern Gaza Strip early on Thursday, shortly after militants fired a rocket at Israel, witnesses and the Islamic movement Hamas said.

An Israeli military spokesman confirmed the attack, saying it had targeted a weapons production site, in response to the rocket fire at Israel.

There were no immediate reports of any injuries from the attack which witnesses said damaged a metal foundry in the town of Rafah, along the Gaza Strip border with Egypt. The air strike was at least the second time Israel has bombed Gaza since a Jan. 18 halt to a 22-day offensive.

Israel bombed tunnels on Wednesday it says were used to smuggle weapons from Egypt into Gaza, a day after Gaza militants killed an Israeli soldier in an explosion along a border fence.