Abuja - Nigerian police on Tuesday blocked supporters of 219 schoolgirls kidnapped by Boko Haram militants from marching on the president's official residence on the six-month anniversary of the abduction.
A wall of female officers in full riot gear formed the first line of a barricade in front of less than 100 members of the Bring Back Our Girls campaign, preventing them from setting out.
An AFP reporter at the scene estimated that the security forces outnumbered the protesters by 10 to one, as they chanted: "Bring back our girls now and alive!"
Elsewhere in the capital, about 300 youth members of Goodluck Jonathan's ruling Peoples Democratic Party (PDP) took over a park where the demonstrators normally meet.
Also read: Chibok girls protest: Security beefed up around
It was not immediately clear why the march was blocked and several government ministers came out to address the noisy crowd, who are seeking to keep the girls' disappearance in the global spotlight.
Meanwhile, the United States reaffirmed its commitment to helping Nigeria find the group while Britain's former prime minister Gordon Brown said the world should not forget the girls' struggle.
Hadiza Bala Usman, who helps to coordinate the protests in Nigeria, said they have struggled to keep the issue in the public eye, with no news about the girls and often open hostility.
"It's just about being here everyday even if it's just for an hour," she told AFP.Pressure, intimidation
The activists, born out of a viral social media campaign backed by US First Lady Michelle Obama and celebrities, were forced to move from the park where they held a candlelit vigil on Monday evening.
Self-styled PDP "partisans" hung around at the venue on Tuesday. Asked where the protesters were, one of them, who gave his name as Sunday Markus, said only: "They have left this place."
Campaign spokesman Olatunji Olanrewaju called the youths a "rented crowd" and added: "We have been assaulted by such people in the past and we had to relocate."
Some 276 girls were seized from their dormitories at the Government Girls Secondary School in the remote town of Chibok in Borno state, northeastern Nigeria, on the night of April 14.
Fifty-seven escaped and Boko Haram leader Abubakar Shekau later vowed to sell the rest as slave brides and said they would not be freed until militant prisoners were released from jail.
Families affected by the attack have run the gamut of emotions over the last six months, with talks at a standstill and despite the military claiming that they knew where the girls were held.
Usman said at that at the height of the frenzy, activists believed that a resolution was imminent and that Nigeria would be forced to make a deal with the Islamists.No injustice can last forever
Many in Chibok "have already lost hope", said Mutah Nkeki, an Abuja resident from Chibok, whose two nieces aged 17 and 19 were among the hostages.
But Enoch Mark, an elder in Chibok whose daughter and nieces are being held, said the recent escape of a woman kidnapped by Boko Haram nine months ago in a separate attack had given fresh hope.
"If this girl could regain freedom after nine months in captivity all hope is not lost. We are ready to wait six years on hoping to have our daughters back with us," he said.
Brown also said the woman's release and that of 27 hostages freed in Cameroon last weekend was a "ray of hope" for the girls' eventual freedom.
But both Mark and another Chibok elder, Pogo Bitrus, dismissed reports that four of the missing girls had escaped to Cameroon.
Outside Nigeria, activists were still trying to keep interest alive, using online petitions to calls for action on Facebook and Twitter.
In Washington, national security adviser Susan Rice said the United States would "continue to work toward the release of all the girls who remain in captivity".
Brown said in an article on The Guardian's website that he was encouraged about the surge in interest in promoting education worldwide but warned that results were needed soon.
"The Nigerian girls are still foremost in our mind, or should be. Their fight against their abduction will be won some day. No injustice can last forever.
"But for the sake of these girls, it must be won soon," he wrote.