Saudi Arabia and the United Arab Emirates are using Bahrain as "trial balloons" for warmer ties with Israel, the Haaretz daily reports.

An Israeli delegation traveled to Bahrain for a UNESCO event in Manama last month, with the paper describing the visit as “not trivial” because it could signal a shift with regard to the tiny Persian Gulf state's treatment of Israel.

“Arab countries that don’t officially recognize Israel have insisted over the years on not granting entry to Israelis, even when hosting major international events,” the Israeli newspaper wrote.

It quoted experts in Washington as saying that even though official relations between Bahrain and Israel aren’t “around the corner,” ties are indeed getting warmer.

Bahrain’s Foreign Minister Khalid bin Ahmed Al Khalifa surprised the world in May when he supported Israel's attack on dozens of military targets in Syria.

He twitted that Tel Aviv had a right to "defend itself" as he signed up to the Israeli version of a chain of events that cited the raid a response to an alleged Iranian rocket attack against military bases in the occupied Golan Heights.

“It makes a lot of sense for Bahrain and Israel to increase their cooperation,” Haaretz quoted Jonathan Schanzer from Washington-based think tank the Foundation for Defense of Democracies as saying.

Schanzer visited Bahrain last year as the Arab country's rulers "are testing the waters and the trend is very clear” for a possible normalization with Israel.

Bahrain is a bellwether for other Persian Gulf Arab states, such as the United Arab Emirates and Saudi Arabia, which also view Israel as a potential partner against the Islamic Republic of Iran, Haaretz said, citing Schanzer.

“It seems sometimes like Saudi Arabia and the UAE are using Bahrain – which is allied with them but is smaller and less influential – to do ‘trial balloons’ regarding foreign policy. It’s true with regard to the three countries’ rivalry with their neighbor Qatar, and also with regard to Israel,” he said.

Manama’s overtures to Tel Aviv have been met with strong public scrutiny, with the people in the Persian Gulf kingdom holding numerous protest rallies against normalization of ties with Tel Aviv.

In May 2017, Manama witnessed the first visit of an Israeli official at the 67th congress of football’s world governing body FIFA. That visit prompted the hashtag "#Bahrain_refuses_normalization" to go viral.

The kingdom became the only Persian Gulf country in 2016 to publicly mourn the death of former Israeli president Shimon Peres.

Also that year, Manama officials raised eyebrows by hosting and participating in an Israeli celebration in Manama, where Bahraini dignitaries and traders danced next to rabbis.

In September 2017, Israeli newspapers quoted a rabbi who had met with the Bahraini king as saying that the ruler had opposed the Arab states’ boycott of Israel and intended to allow citizens from his kingdom to visit the occupied territories.

Last December, the Bahraini king sent a delegation to Israel “with a message of peace to the whole world,” the Times of Israel reported.

Rev. Johnnie Moore, an evangelical Christian leader who led the Bahraini delegation, stressed that normalization of relations between Bahrain and Israel was “inevitable.”

"There are many cooperations that are happening all the time. Most of them are kept secret,” he told Haaretz.

He noted that he was surprised when Bahrain did not cancel the trip following the US President Donald Trump’s decision to recognize Jerusalem al-Quds as Israel's “capital."