ANTANANARIVO, Madagascar (AP) _ Opponents of President Didier Ratsiraka said another of their leaders was seized by security forces today, but protesters rallied again in defiance of a ban on public gatherings.

Thousands of demonstrators gathered outside the Public Works Ministry, one of six ministries taken over by the opposition in its campaign to install a self-declared government.

According to protesters, the opposition leader named as the public works minister, Rahantavololona Andriamanjato, was taken from the ministry by a dozen masked security officers early in the day. Her husband, the Rev. Richard Andriamanjato, is chief spokesman for the opposition coalition.

Two other ministers in the opposition's self-declared government were arrested Tuesday when Ratsiraka's government declared a state of emergency banning public gatherings, imposing press censorship and instating a curfew.

Despite the decree, troops have been reluctant to confront the huge crowds of demonstrators, who have taken to the capital's streets almost daily since June 10. The opposition began taking over ministries peacefully on Monday.

In the wake of Communism's downfall in eastern Europe, a wave of strikes, riots and protests has swept across Africa the past 18 months, forcing 16 one- party states to legalize political opposition.

Three Marxist governments have been unseated at the ballot box, and more are expected to fall in multiparty elections scheduled in several other countries.

Ratsiraka's government has made no public statements on the showdown in recent days, other than to reiterate the provisions of the state of emergency.

The opposition demands Ratsiraka's ouster, replacement of the socialist constitution and free multiparty elections.

Ratsiraka was elected to a third seven-year term in 1989, when his party won control of Parliament in elections that the opposition contends were rigged.