The Africa Regional Manager for International Christian Concern (ICC) is asking U.S. citizens to contact their Congressional representatives on Leah Sharibu’s behalf.

“We still have a lot of pull in Africa and Nigeria,” Nathan Johnson told The Stream. “If the United States was to pressure the Buhari government, then it may help.”

Leah, 15, was captured along with over 100 classmates in February from an all-girls school in Dapchi, Nigeria. Boko Haram released the rest of the girls in March. But they kept Leah captive for refusing to renounce Christ. She was the only Christian among the schoolgirls.

In August, Boko Haram released an audio recording of Leah begging for assistance from the Nigerian government. Earlier this month, they threatened to kill her.

“People need to pray for Leah’s safety,” Johnson said. And “that the government would have some breakthrough in finding her, or decide to pay a ransom.”

Leah’s Voice

In the audio recording released last month, Leah calls on the Nigerian “government and people of goodwill to get me out of this problem.”

Leah’s father, Nathan Sharibu, told CNN the voice in the recording is definitely his daughter’s.

“I thought she might have been killed since we were told by those released that Boko Haram kept her because she is a Christian,” he said. “I can only imagine the way they would have treated her.”

Johnson previously told The Stream Leah was likely to undergo intense psychological pressure to convert to Islam, if not physical torture.

According to a report by Open Doors USA, the pauses in the audio recording indicate Leah was reading from a written statement.

Killing Female Captives

While Leah was in danger before, the situation is growing even more dire.

Earlier this month, Boko Haram killed Saifura Hussaini Ahmed Khorsa. The 25-year-old midwife, affiliated with the Red Cross, was captured alongside two other female aid workers.

At the time, Boko Haram threatened to kill the other two aid workers and Leah.

Such a move is atypical for the terrorist group, according to Johnson. They have not been known to kill female captives in the past, especially Muslim captives. Johnson said it is believed that Khorsa was Muslim.

“This means that there is an increased chance that Leah is in danger,” he told The Stream.

Why would Boko Harma begin killing female captives now? Johnson said there are two possibilities. Either the group is growing stronger and more aggressive, or they are running out of money and growing more desperate. The first is more likely, he believes.

A Plea for Prayers and International Pressure

Despite increased international attention on Leah’s plight, the Sharibu family has yet to hear from the Nigerian government, Johnson said. In a video released earlier this month, Mr. Sharibu thanks Christians and Muslims around the world for their prayers.

The video, posted by ICC, features Leah’s father, mother and brother asking for help in securing Leah’s release.

“I’m pleading to the world concerning my daughter Leah to put pressure on the Federal Government of Nigeria for her return,” Mr. Sharibu says.

He also asks “Christians in the whole world to keep on praying for Leah and the family.”

Watch the video below. Click here to find out how to contact your representatives.