Smoke rises from an explosion caused by an Israeli airstrike in Gaza City. Picture: Hatem Moussa/AP

Tel Aviv/Gaza City - Palestinian militants fired over 100 rockets from the Gaza Strip into Israel on Saturday, prompting the Israeli army to respond with multiple airstrikes, killing one man.

Gaza's Health Ministry said in a statement that Mohammad Nasser, 22, was killed in an Israeli airstrike on the northern Gaza Strip.

The ministry said six others were injured in Israeli strikes.

Media outlets reported that three of them were civilians; there was no information available yet regarding the other three.

The army said fighter jets and tanks were striking Hamas and Palestinian Islamic Jihad targets in Gaza.

Israeli media reported that a woman was seriously wounded by shrapnel in her face when a rocket fell near a school in the city of Kiryat Gat. There were also reports that a 35-year-old woman was moderately injured, sustaining wounds to her limbs in the city of Ashkelon.

Smoke rises in the Israeli city of Ashkelon following a rocket attack over the border between Israel and Gaza, as seen from the Israeli side of the border. Picture: Amir Cohen/Reuters

One rocket also directly hit a house in the Ashkelon Regional Council, police said. The residents of the house had managed to make their way to a safe zone after sirens went off.

Another house was also hit in a community near the border.

Sirens continuously wailed in Israeli communities near the border with Gaza, warning residents to take shelter. Sirens also rang out in communities in the south-centre of the country.

There was also heightened security and police presence in cities in the south.

The Iron Dome aerial defence system intercepted dozens of projectiles.

Israeli security officials held an emergency meeting in light of the the escalation.

Early Saturday, the army announced that "following the situation assessment, it has been decided in the IDF (Israel Defence Forces) to block areas and routes adjacent to the security fence with Gaza."

This came after four Palestinians were killed and 51 injured in clashes with Israeli forces along the border fence on Friday. Two Israeli soldiers were wounded by Palestinian gunfire.

The clashes came during weekly anti-Israel protests in the eastern Gaza Strip.

Two of those killed were demonstrators, Gaza authorities said, and two were Hamas militants, according to Palestinian security sources.

The two militants were killed in an Israeli airstrike on Friday on a Hamas training facility. The strike came shortly after gunmen opened fire at an Israeli army force stationed on the border with eastern Gaza Strip and wounded two soldiers; one of them sustained moderate injuries while the other suffered light injuries.

Various Gazan militant groups were firing barrages of rockets from the Gaza Strip into Israel on Saturday in response to the Palestinian casualties killed on Friday.

An Islamic Jihad spokesman said that his movement will deprive Israel the opportunity of "succesfully holding any festival that targets the Palestinian narrative."

The Eurovision Song Contest is set to open in Tel Aviv in less than two weeks time.

Mus'ab al-Briem, Islamic Jihad's spokesman in Gaza, told reporters that "hell is the fate of the [Israeli] settlers' lives in light of the continuation and expansion of the aggression of the Zionist occupation on our people and our resistance."

"We tell the Israeli occupation's war decision makers: Never dream of having calm as long as the Palestinian people pay the price," he said.

Abdulatif al-Qanou'a, Hamas' spokesman in Gaza, said in a press statement: "The current understandings [for calm] will not be a barrier to respond to the aggression of the occupation. The blood of our people is a red line that can't be overcome."

The escalation comes following a period of relative calm amid Egyptian efforts to negotiate a ceasefire between Israel and Hamas, following the most recent flare-up at the end of March.

Hamas is classified by the EU, Israel and the US as a terrorist organization.

Israel and Egypt have imposed a blockade on Gaza for over a decade, citing security reasons.