Arab participation in Israel's national service programme is skyrocketing, with a 650 per cent increase recorded over the last six years.

When President Reuven Rivlin met a group of volunteers earlier this month, he was surprised to hear that Arab enrolment outstrips the number of registered Charedim by three to one.

Arabs and Charedim are the two sectors of Israeli society exempted from compulsory military or civil service.

Sar-Shalom Jerbi, the director of the national service programme, told Mr Rivlin that there are 4,500 Arabs taking part today, compared to 600 six years ago. Around 100 of these are not even citizens of Israel, but rather Jerusalemites who are classed as "permanent residents".

Ahmed Zatrah, a young Arab man from the village of Ein Nakuba west of Jerusalem, was driven to volunteer in a police station by a sense of duty, and also feels that it will help his career and university prospects. "It's good for me and I wanted to help the police and the state," he said in an interview on Tuesday, adding: "It will help me in the future."

He dismissed the mainstream view of Israeli-Arabs that national service is unacceptable, saying: "The police is for all citizens, Jewish and Arab."

While Mr Zatrah was happy to discuss his service, many Arabs keep quiet in their communities about their decision to volunteer and confide only in a few close friends - disapproval in Arab society is widespread.

Volunteers can sometimes face threats of violence, even though around 85 per cent of them are given roles that mainly help fellow Arabs.

Mr Jerbi recalled several examples of volunteers facing negative consequences. "One girl volunteered in a hospital and, the day after she started, the windows of her car were smashed and her tyres were slashed," he said.

The mainstream Arab leaders in Israel shun such violent reactions and say that they do not condemn volunteers, but strongly disapprove. Mohammad Zeidan, director of the Nazareth-based Arab Association for Human Rights, said that he would "definitely" discourage his children from taking part and said: "There is a consensus against military service and national service."

He saw the push to get some Arabs serving as a pretext for Israel to question the loyalty of the majority who do not serve, and as such justify "discrimination" against them.

Mr Zeidan interpreted volunteering as an economic phenomenon, arguing that work can be hard to find and national service brings a monthly stipend, a grant for university study and other perks.

However, some describe their participation as a display of their attachment to Israel. Mr Zatrah even took part in the recent delegation of volunteers to the president's residence, and told Mr Rivlin of his desire to help the state of Israel.

Mr Rivlin ended the meeting with a clarion call that delighted his guests but irked the Arab establishment. "I call on Israel's Arab citizens to join national service," he said. "We are one society."