Israel has restored the fishing zone off the coast of Gaza to six nautical miles, after reducing it to three in March when rockets were fired from the territory, the army said on Tuesday.

"Prime Minister Benjamin Netanyahu and Defence Minister Moshe Yaalon have approved the extension of the fishing zone in the Gaza Strip from three to six nautical miles," an army statement said.

"The fishing zone was restricted in the first place because of rockets fired on southern Israel on March 21," it added.

The restriction was imposed after militants fired two rockets at southern Israel on March 21, one of which caused damage to the yard of a house in the town of Sderot, during a three-day visit by US President Barack Obama.

They were slammed by Israeli human rights groups who said it was little more than "collective punishment."

A number of rockets have since hit southern Israel from Gaza, several of them claimed by hardline Salafist group the Mujahedeen Shura Council.

Since March, there has been an escalation of rocket fire on southern Israel after more than three months of complete quiet following a deadly confrontation in November which ended with the Egyptian-brokered truce deal.

Israel's most direct retaliation was an April air strike against a member of the MSC it said was involved in a rocket attack launched from Egypt's Sinai Peninsula that month.