Israeli helicopters fired missiles in two locations in Gaza early Wednesday, residents said, sending plumes of black smoke into the air over Gaza City (search).

Two missiles struck the Zeitoun neighborhood in Gaza City, and a third hit near the Erez checkpoint between Gaza and Israel at the northern edge of the Gaza Strip (search), residents said.

The Israeli military had no immediate comment.

It was not known what the targets were or whether there were casualties.

In the past, Israeli helicopters have targeted metal workshops where the Israelis say militants manufacture weapons, including crude missiles they fire at Jewish settlements in Gaza and Israeli towns just outside Gaza.