The surge in religiously-motivated discrimination against women in the military could pose a threat to Israel's security, a group of retired major generals warned in a letter on Monday.

The warning, which related to the rising tensions between religious male soldiers and female soldiers, was laid out in a letter signed by 19 major generals addressed to Defence Minister Ehud Barak and Chief of Staff Benny Gantz which was published in Haaretz newspaper.

In the text, the signatories point to a slew of recent events where women soldiers were pushed aside in favour of the religious sensitivities of observant male soldiers.

They also pointed to demands to stop women from training male soldiers and to remove them from mixed fighting units, to several recent instances of gender-separated army celebrations, and moves to prevent women soldiers from singing at events attended by men.

Barak and Gantz must act to "prevent harm being caused to women soldiers... so as to stop the rolling snowball, a snowball which is liable in future to harm the security of the state of Israel and the fundamental values of Israeli society as a whole," it said, without elaborating.

The letter, a rarity coming from such senior and loyal members of the military establishment, was written out of concern "for the image of the Israeli army as the people's army, (in order) to maintain its strength, the security of the state and Israeli society's fundamental democratic values," it said.

The Israeli army has in recent years been increasing efforts to encourage ultra-Orthodox men to enlist, partly through creating special units in which these extremely conservative recruits will not be exposed to female soldiers.

In recent months, gender segregation has become much more prevalent among the national-religious public, which unlike the ultra-Orthodox, will serve in any position in the army.

"We cherish the religious soldiers and respect their rights, but these should be regulated without imposing religious norms or life-styles on the rest of those in their military service," the letter said.

Gantz recently asked the head of the army's personnel directorate to re-examine issues arising from the joint military service of women and religious soldiers, Haaretz said.

The defence ministry had no immediate response to the letter, while the army expressed frustration over its publication "before receiving the due attention of those it was sent to."