Israel's hard-line approach to speculation that Iran is seeking to develop a nuclear weapon could have "catastrophic consequences", a senior Russian foreign ministry official warned Thursday.

"The inventions" concerning the possible development of nuclear arms by Iran "are increasing the tension and could encourage moves towards a military solution with catastrophic consequences," Mikhail Ulyanov told the Interfax news agency on Wednesday.

Half a million Israeli public and private sector workers began a general strike on Wednesday, shutting down government offices, banks and airport traffic over the rights of contract workers.

Trade union umbrella group Histadrut announced the general strike would go into effect early on Wednesday morning, after late-night talks between the powerful association and the finance ministry broke down.

Vandals scrawled anti-Arab and anti-Christian slogans on a monastery and a school in Jerusalem overnight, Israeli police said on Tuesday.

Police spokesman Micky Rosenfeld said unknown people sprayed graffiti reading "death to Christians" and "price tag" on the walls of the Greek Orthodox Monastery of the Cross in west Jerusalem overnight.

Israel will reportedly take the necessary measures to halt any attempt by the Syrian regime to transfer large amounts of highly developed weapons to “terrorist organizations” including Hizbullah as violence is mounting in the country.

Israel’s Haaretz newspaper reported on Tuesday that the escalating threat against President Bashar Assad’s regime is raising the Israeli officials’ concerns over the possibility of “terrorist groups” obtaining weapons from Syria.

A rocket fired by Palestinian militants from the Gaza Strip hit southern Israel late on Monday causing no casualties or damage, an Israeli military spokeswoman said.

"A Qassam rocket hit an open field in the Sha'ar Hanegev regional council," the spokeswoman told Agence France Presse.

Israeli Prime Minister Benjamin Netanyahu has warned his officials to stop "blabbing" about the possibility of an attack targeting Iran's nuclear program, the newspaper Maariv reported on Monday.

Netanyahu is said to have directed the instruction at a number of military officials and government ministers who he believes have been speaking too freely about a potential Israeli attack on Iranian nuclear facilities.

U.S. President Barack Obama said Sunday he did not think Israel had made a decision on whether to launch a pre-emptive strike on Iran's nuclear installations, a threat that has rattled the region.

Obama -- seeking to reassure Americans over the danger posed by Tehran's suspect nuclear program, and any negative side-effects for the United States -- said Washington was working "in lockstep" with Israel to bring Iran to heel.

Prime Minister Benjamin Netanyahu said on Sunday that economic and military might are Israel's only guarantee for peace and security following the latest developments in Iran and Syria.

"In the past few days we received a reminder of what kind of neighborhood we live in," Netanyahu said at the start of the weekly cabinet meeting.

Lebanon must not hesitate in supporting the regime of Syrian President Bashar Assad, because backing it has major “strategic and fateful” repercussions, sources close to Hizbullah told the Kuwaiti al-Rai newspaper in remarks published on Sunday.

They said: “Hizbullah will not allow the fall of the Assad regime even if it means launching a war with Israel.”

Saboteurs on Sunday blew up a pipeline that supplies gas to Israel, the 12th such attack in a year, security officials said.

Masked gunmen planted explosives under the pipeline in the Al-Massaeed area, close to the town of El-Arish in the north of the Sinai Peninsula, they said.