JERUSALEM (Reuters) - Threatening slogans were daubed on Monday outside the doorway of an Israeli activist in a Jewish women's prayer group seeking equal rights of worship for women at Jerusalem's holy Western Wall.

"Your time is up," read one of several slogans spray painted in black in the apartment building where Peggy Cidor, a board member of the Women of Wall movement lives.

Police spokesman Micky Rosenfeld said it was "the first incident of its type in which one of the Women of the Wall houses are directly targeted".

The group has angered ultra-Orthodox Jews by wearing prayer shawls and reading from holy scriptures at the Western Wall, a revered remnant of the Biblical Jewish Temple.

Orthodox Jewish tradition reserves such rituals for men, and some more conservative rabbis have vowed to battle a plan devised by a former cabinet minister to try to accommodate the women's more liberal approach to prayer.

Previously, the women have been confronted by protesters at the holy site itself and some have also been detained by police for allegedly violating statutes governing the site, although last month an appeals court overruled police on these arrests.

"It's okay to disagree with us, but words can also be dangerous," Cidor, referring to the graffiti, told Reuters.

The prayer issue is at the heart of a lifestyle struggle between Israel's secular majority and an ultra-Orthodox minority in a country where most religious ritual and institutions that oversee marriage, divorce and burial are controlled by Orthodox authorities.

Earlier this month, Israeli police held back thousands of ultra-conservative Jews who threw chairs and water at the women who turned out for a monthly worship session at the Western Wall.

(Writing by Allyn Fisher-Ilan; Editing by Jeffrey Heller and Alison Williams)