Demonstrators are to march through the Nigerian capital Abuja to press for the release of more than 200 schoolgirls abducted by militants two weeks ago.
They say they will march to the National Assembly and demand more action from the government, which has been criticised for not doing enough.
The Islamist group Boko Haram has been blamed for abducting the girls from their school in Chibok, Borno state.
Boko Haram has not yet made any response to the accusation.
The group, whose name means “Western education is forbidden” in the local Hausa language, has been blamed for 1,500 deaths in attacks this year alone.
A “million-woman protest march” has been called by the Women for Peace and Justice organisation on Wednesday to demand more resources for securing the girls’ release.
Anger has mounted in recent days. Parents have criticised the government’s search and rescue efforts and the number of missing girls has been disputed.
March organiser Hadiza Bala Usman told the BBC that the women wanted to know why soldiers seemed so ill-equipped to find the girls.
She warned that the abductions would discourage parents from sending their daughters to school in an area where few girls are given an education.
Saruta, a woman from Chibok, told the BBC’s Newsday that the community was desperate for help.
“For how long are we going to wait for the government to help us? We can’t bear it anymore. We can’t,” she said, breaking down in tears.
“We just want the government to help us, we want the whole world to hear this and help us,” she said.
On Tuesday, a local official said some of the girls may have been taken to neighbouring states and forced to marry the militants.
Mr Bitrus, a Chibok community leader, said 43 of the girls had “regained their freedom” after escaping, while 230 were still in captivity. He was adamant that this figure – higher than previous estimates – was correct.
Swathes of north-eastern Nigeria are, in effect, off limits to the military, allowing the militants to move the girls towards, or perhaps even across, the country’s borders with impunity, says the BBC’s Will Ross in Abuja.
The government has said the security forces are searching for the girls, but its critics believe more could have been done.
The students were about to sit their final year exam and so are mostly aged between 16 and 18.
Boko Haram leader Abubakar Shekau first threatened to treat captured women and girls as slaves in a video released in May 2013.
It fuelled concern at the time that the group was adhering to the ancient Islamic belief that women captured during war are slaves with whom their “masters” can have sex, correspondents say.