Israel continued to bomb Palestinian militant targets in Gaza, including the media operations of Hamas, from the sea and air on the fifth day Sunday, news agencies reported.

Missiles hit two buildings used by both Hamas and foreign media in the center of Gaza City, injuring several Palestinian journalists, the Associated Press reported.

Militant rocket fire into Israel resumed Sunday morning after an overnight lull, with three rockets fired at the nearby coastal city of Ashkelon, Reuters reported, citing the Israeli military.

Since the beginning of fighting 48 Palestinians, about half of them civilians, including 13 children, have been killed, Reuters reported, citing Palestinian officials. Three Israelis have also been killed, with more than 500 rockets fired from Gaza since Wednesday.

Israeli Vice Prime Minister Moshe Yaalon said more than 1,000 Palestinian targets have been hit, “so Hamas should do the math over whether it is or isn't worth it to cease fire.”

"If there is quiet in the South and no rockets and missiles are fired at Israel's citizens nor terrorist attacks engineered from the Gaza Strip, we will not attack," he wrote on Twitter.

The military, on its official Twitter account, said that the sites it hit Saturday night were “all positively identified by precise intelligence over the course of months.”

An Arabic-language recording was repeatedly broadcast over the radio stations of Hamas and the Islamic Jihad militant group, apparently by the Israeli military, warning the people of Gaza to stay away from Hamas installations and personnel.

"To the people of Gaza, Hamas is playing with fire and gambling with your fate," said the message, which was broadcast every five minutes. "The Israeli Defense Force is moving toward the second phase of its operation. For your safety, you should stay away from Hamas infrastructure and personnel."

Though it wasn’t clear what the “second phase” was, thousands of Israeli troops are stationed near the Gaza border apparently awaiting orders for a ground invasion.

The Israeli Cabinet Friday authorized the mobilization of as many as 75,000 reservists to prepare for a possible ground invasion.

Israel killed a Hamas military leader Wednesday, triggering intense fighting. Israel has declared that its goal is to exhaust militant arsenals and thwart cross-border rocket fire by Hamas that has plagued Israeli border towns for years.