A spate of epithet-laced attacks by young Israeli Jews against Arabs indicates anti-Muslim and anti-Arab bigotry is becoming more acceptable in many sectors of Israeli society, according to rights workers.

Police have arrested four people, including two minors, over the bludgeoning on Saturday of an Arab Israeli citizen on holiday with his wife in the Israeli city of Tiberius, Israel's Yedioth Ahronoth newspaper reported this week.

That was at least the fourth attack in Israel in the last month targeting Palestinians and Arab citizens, about 20 per cent of Israel's population of 7.7 million people.

Yesterday, Israel's police commissioner, Yohanan Danino, called on his officers to be vigilant against such attacks, which he described as "despicable and criminal".

"This is our response to any expression of racism," he said at a meeting in Tel Aviv called to assess the issue.

Although lacking statistics, Israeli rights groups and politicians said such incidents were on the rise because of the influence of ultranationalist Jewish parties in Israel's parliament over the last decade and xenophobic blowback from the nearly 46-year occupation of the Palestinian territories.

The attacks, which authorities have described as "nationalistically" motivated, seem to be carried out primarily by religious Jewish men in their twenties or younger.

Auni Banna, the director of the Arab minority rights department at Association for Civil Rights in Israel (ACRI), partly attributed the violence to years of "institutionalised" discrimination against Arab citizens, who face restrictions on land ownership and access to housing and education not experienced by Jewish citizens.

Nadeem Shehadeh, an attorney at the Legal Center for Arab Minority Rights in Israel, or Adalah, said attitudes of Jewish Israelis had increasingly become almost blasé towards anti-Arab violence and discrimination.

"These sort of incidents have become common in the sense that nobody condemns you if you say or do something that's really racist, because there's this increasing sense of tolerance for this kind of stuff," he said.

The victim of Saturday's attack, Nimer Sharkawi, said he was singled out after the attackers discovered his ethnicity, telling him "Arab, get out" before smashing his face with an unspecified object.

"They knew we were Arabs because I spoke Arabic to my wife. They started cursing and then attacked like maniacs. I asked them: 'Why? What did I do to you?'," Mr Sharkawi, 43, told Yedioth Ahronoth.

He was treated at a nearby hospital for a broken jaw.

The newspaper reported that two of the four suspects arrested by police were involved in another attack last month on an Israeli-Arab man, Hassan Usruf, a Tel Aviv street cleaner in his 40s.

As many as 20 Jewish youths reportedly beat Mr Usruf with glass bottles, sending him to hospital with wounds to his jaw, eye socket and head.

"'You're an Arab. You want a state? Is that what you want?'" Mr Usruf recalled of his attackers' threats from his hospital bed late last month to Israeli media.

Young men are not the only attackers. Last month, a group of Jewish-settler women were photographed beating a female Palestinian, Hana Amtir, on Jerusalem's light-rail train system.

"Four young women came to me and asked me whether I was Arab. I said yes, you can tell by my clothes. After that they spat on me and one of them started to shout 'Arab, Arab'," Ms Amtir told Israel's Channel 10 television on Sunday, adding that the assailants punched and kicked her in the stomach.

What was once usually manifested in bigoted remarks uttered at football matches or shopping centres now seems to be increasingly vented through violence. Mr Banna, the ACRI official, said Israel's political drift to the right and a recent spate of discriminatory measures introduced by its right-wing government shared a portion of the blame for the violence.

Such measures include the cabinet's passage of loyalty oaths by potential immigrants to Israel as a "Jewish state" and a law that critics say allows Jewish communities in the Negev desert and the Galilee, areas with large Arab populations, to vet prospective residents based on religion and race.

"If a Jewish Israeli sees his government as portraying Arabs as a threat and a fifth column, why wouldn't he feel the same way?" Mr Banna said.

He also attributed the attacks to anti-Arab sentiment fostered by Israeli settlers living in the occupied Palestinian territories. Emulating so-called price-tag attacks against Palestinians in those areas, Jewish extremists have increasingly turned to desecrating Muslim holy sites inside Israel.

Haneen Zoabi, an Arab member of Israel's parliament, said the attacks against Arab citizens have forced them to ponder more than just the institutionalised discrimination they face in terms of land ownership and employment. Increasingly, they fear for their safety.

"The violence is getting worse because there's this atmosphere of legitimacy for these incidents, which are almost accepted by society and of course the political system," she said.

"It's not just an issue of equality for us anymore - it's about security."