Nigerian President Goodluck Jonathan has demanded that more effort be made to free 223 schoolgirls whose abduction by suspected Islamists has sparked international outrage.

The angry reaction to the government’s ineffectual response has been heightened after two girls who escaped told of their dead-of-night ordeal.

Jonathan has come under mounting pressure since gunmen believed to be Boko Haram extremists stormed the girls’ boarding school on April 14, forcing them from their dormitories onto trucks and driving them into the bush.

Anger at his government’s slow response has fuelled protests at home and abroad, including in New York where dozens of Nigerians staged a demonstration on Saturday demanding that more action be taken.

Many carried signs saying “free our daughters” and “we say no to our daughters’ abduction”.

A meeting on Sunday brought together for the first time all key players in the search for the missing girls, from Nigeria’s military and security service chiefs to Borno state’s governor and police chief, and the head of the girls’ school in Chibok.

Police on Friday said kidnappers were still holding 223 out of 276 girls seized from the northeastern school – higher than previous estimates of the number being held.

A Nigerian newspaper on Sunday published an interview with two of the girls who got away, who told of their abduction and “desperate” escape.

To hear that over 200 girls are missing in Nigeria and no one is doing much about it brings pain to my heart. #BringOurDaughtersBack

— Ms. Dortheá Enrique (@DortheaThomas) May 4, 2014

Both girls told of how they summoned the courage to jump off the trucks driving them into the bush.

“Our vehicle developed a problem and they were forced to stop. I took the opportunity with some girls to run into a dark bush,” Thabita Walse told The Sunday Punch.

“I have heard a lot about Boko Haram, the bad things they do and how they have killed many people in the state,” said Sawok. “I was afraid and I became desperate.

“I felt getting to their camp could be dangerous for me, and it would be better if I escaped. That gave me the courage to jump out.”

Boko Haram’s name translates as “Western education is forbidden”, and it has repeatedly attacked schools during an insurgency aimed at creating a strict Islamic state in mainly Muslim northern Nigeria.

US Secretary of State John F. Kerry has pledged his country’s assistance in the search.

“The kidnapping of hundreds of children by Boko Haram is an unconscionable crime,” Kerry said on Saturday. “We will do everything possible to support the Nigerian government to return these young women to their homes and hold the perpetrators to justice.”

The issue is also trending on social media, with many calling for the safe return of the young women with the hashtag “#BringBackOurGirls”.

-with AAP