Jerusalem: In a major escalation, at least 10 people were injured in a barrage of rocket fire from Gaza on Israel's southern territories on Friday, a day after eight Israelis were killed in a Palestinian attack.

The sudden spurt in violence prompted the Israel to warn that it would respond with strength "exacting a price, a very heavy price" if such attacks continue.

On Thursday, heavily armed militants from Gaza had infiltrated into southern Israel through Egypt's Sinai Peninsula, launching a series of coordinated attacks claiming eight lives, prompting a reprisal strike that killed six people in the Palestinian territory.

One of the ten rockets fired exploded in the courtyard of an ultra-orthodox yeshiva (institute for religious studies) in the southern city of Ashdod leaving 10 people injured.

The Magen David Adom emergency services said that two people sustained serious wounds to their abdomen. Eight others were slightly injured in the attack.

The victims were rushed to the Kaplan Medical Centre in Rehovot.

The barrage of grad and qassam rockets also hit other major population centres in south Israel such as Ashkelon, Be'er Sheva and Kiryat Gat, causing no major damages.

The Home Front Command issued guidelines for residents of southern communities banning the gathering of more than 500 people.

Beersheba Mayor Rubik Danilovitch called on residents to adhere to the defence establishment instructions.

An anti-missile Iron Dome battery, which has proved useful in intercepting short range rockets, was deployed in the city.