The woman was discovered in the back of a taxi that was stopped by police for inspection.
Police captured a female resident of Tayibe suspected of planning to carry out a terrorist attack in Nahariya on Monday night, according to reports by police.
A security warning was issued earlier on Monday evening for Nahariya after warnings a woman was planning to carry out a terror attack in the city.
Police then set up roadblocks and began inspecting cars in the area. The suspect was discovered riding in a taxi that was stopped by a roadblock.
The suspect was taken into custody by police officials for further questioning.
Earlier on Monday, a terror alert prompted security forces to set up roadblocks and heighten security across the Lachish region in southern Israel, according to a statement by Israel police.
The alert was issued in the municipality of Sderot and its surrounding areas.
Border Police officers reinforced border crossings in the region as part of the security effort.
Police gave no further details of the warning by mid morning, but called on the public to exercise caution and to report suspicious persons to police.