When 29-year-old A. comes home on leave, her parents and friends are unaware of where she's been to and the perils she's faced.

"A." is the first and only woman to serve in "Yamas," an undercover unit that operates within Israel's paramilitary Border Police. The seven-year veteran and her elite team track down fugitive Palestinian militants in the West Bank and east Jerusalem.

"When I leave the base, I prefer to keep everything to myself, and not let family and friends in on what I do. Even my fiance knew only a year after we met what I really do," said A., whose first and surname are confidential.

Touted as "the most secret combatant in the security establishment," up until her first-ever interview with the Ma'ariv daily, A. disclosed that she and 11 others were selected from among 99 candidates who applied for the grueling eight-month training course.

The recruits learn counter-terrorism techniques, comprehensive weapons training, hand-to-hand combat, tactical driving, undercover work, and other specialized skills.

"I expected chauvinistic treatment, but everyone supported me and wanted to see me succeed -- although I wasn't given any breaks, " she said in a report published on Tuesday.

The revelation that a woman serves Yamas' ranks is stunning in itself: While several dozen women have been flying jets and helicopter gunships in the Israel Air Force since the late 1990s, females are barred from elite ground units and front-line combat.

Until the revelatory interview, only Police Commissioner Yohanan Danino and Border Police commander Yoram Halevy knew of A. 's existence.

The plainclothes unit was established in 1987 after the first Palestinian intifada, and specializes in so-called "chameleon" operations.

Many of the unit's members speak fluent Arabic, and often don local dress during operations targeting Hamas, Islamic Jihad and other militant groups. In preparation, they eat traditional Palestinian fare and smoke local cigarettes, in order to disguise their scent if they encounter suspicious village dogs.

Most teams are deployed in the West Bank and east Jerusalem, and an unknown number along the border with the Gaza Strip.

A. has taken part in hundreds of covert operations: arresting top and junior-rank militants, intercepting suicide bombers en route to Israeli cities, and collecting intelligence in hostile areas.

Her commanders say her work prevented numerous terror attacks and saved many lives.

"She's considered a tie-breaker, the element of surprise in every operation. No one believes that we deploy a woman, which is why she succeeds in blending in perfectly in the field," a senior Border Police officer said.

"In almost every operation we are exposed to danger, and because of my relative advantage as a woman, I am always sent to operate deep inside," A. said.

"The satisfaction that follows the arrest of a militant or a ' ticking bomb' is immense -- knowing that you are saving the lives of many civilians."