A violent explosion lights up the city of Gaza.

Cross-border hostilities here ran into their third day on Sunday (May 5), as new fatalities were reported from both sides and civilians were sent fleeing for cover.

Since Saturday (May 4), Israel's army says Gaza militants have fired more than 400 rockets at Israeli villages and cities.

The latest round of violence flared up on Friday (May 3), when, according to the military, a Palestinian Islamic Jihad sniper fired at Israeli troops.

Two soldiers were wounded.

Israel retaliated with the air strikes which Palestinian officials say killed several people, including a baby and her pregnant mother.

The escalation comes just ahead of both, the Muslim holy month of Ramadan and Israel's Independence Day.

Egyptian mediators, who are credited with brokering ceasefires in the past, are working to put a stop to the violence.

Although aerial exchanges are frequent, Israel and Hamas, the militant group that controls the Gaza Strip, have managed to avert all-out war for the past few years.

Some 2 million Palestinians live in Gaza, whose economy has suffered years of blockades, as well as recent foreign aid cuts.

Unemployment stands at 52 percent, according to the World Bank, and poverty is rampant.

Israel says its blockade is necessary to stop weapons from reaching Hamas, with which its fought 3 wars since the group took control of Gaza in 2007.

Over the past few weeks, Cairo's mediation had helped persuade Israel to lift some restrictions on the movement of goods and people in and out of Gaza and expand the Mediterranean zone where Gazans can fish.

But it scaled back the fishing zone this week in response to rocket fire and shut the border crossings entirely on Saturday.