Israel has embarked on a "secret war" to track down Syria's chemical and biological weapons, the Sunday Times has reported.

As part of the operation, said the Times, Israel has deployed spotters across the border to monitor the movement of Syria's non-conventional arms cache.

“For years we’ve known the exact location of Syria’s chemical and biological munitions,” The Times quoted an Israeli source as saying. “But in the past week we’ve got signs that munitions have been moved to new locations.”

Biological and chemical weapons were first reported in Syria in the 1980s, but the cache has taken center stage of late, as fears grow that Bashar Assad's regime may use such means against rebels.

Syria has been careful not to confirm it has chemical weapons while insisting it would never use such weapons against its own people. The North Atlantic Treaty Organization, meanwhile, voted last week to provide Turkey with Patriot missiles to defend itself, after mortar rounds and shells from Syria killed five Turks.

U.S.­ intelligence has recently detected signs the Syrian regime was moving chemical weapons components around within several sites, according to a senior U.S.­ defense official and two other U.S. ­officials. This type of activity had not been detected before, and one of the U.S.­ officials said it bears further scrutiny.

The White House and its allies are weighing military options to secure Syria's chemical and biological weapons, U.S. officials said last week.

Also last week, journalist Jeffrey Goldberg of The Atlantic reported last week that Israel has asked Jordan twice in the last two months for a green light to attack chemical weapons facilities in Syria.

Prime Minister Benjamin Netanyahu has sent representatives of the Mossad intelligence agency to Amman twice already, to coordinate the matter with the Jordanians and receive their "permission" for the operation, Goldberg wrote.

The Jordanians, however, responded negatively to the request and refused to grant their approval. American officials quoted in the article said the Jordanians told Israel the "time was not right" for such an action.

Jordan's Foreign Minister Nasser Judeh declined to comment on the report that Israel had sought Jordanian permission to strike Syrian WMD sites, but did say his country was monitoring the situation closely and that his government was talking to countries in the region. "We have to be prepared for different scenarios," he said at a press conference, adding that the Syrian regime is currently in control of these weapons and understands that using them would be a "game changer."