A petition calling for religious freedom for Eritrea's Christians has received more than 43,000 signatures.

The petition was handed in to the Eritrean Embassy and 10 Downing Street by the former bishop of Rochester Michael Nazir-Ali, patron of persecution ministry Release International.

Mr Nazir-Ali said: "We want to assure the government of Eritrea that Christians are loyal citizens and present no danger to the integrity of the Eritrean nation.

"We are appealing to the government of Eritrea to allow all Christians freedom of assembly, worship and expression."

Eritrea has been a major campaign focal point for Release International in the last few months. It says more than 2,000 Christians have been imprisoned by the government for their faith, some placed in underground cells or shipping containers where temperatures are freezing during the night and soaring during the day.

As part of the campaign, Release published the book Song of the Nightingale, the first-hand account of gospel singer Helen Berhane who was incarcerated in a shipping container, where she endured terrible conditions, and was beaten by the Eritrean authorities.

It believes tens of thousands of people have fled the country to neighbouring Sudan, Ethiopia and Yemen, passing through crocodile-infested rivers and minefields and running the risk of being shot by border guards who are under orders to shoot on sight anyone attempting to flee the country.

"Those we speak to love their country and want nothing more than to live in freedom as good citizens," said Release International, which serves the persecuted church worldwide.

"Yet many are being hounded out, jailed and tortured for no other reason than their Christian faith.

"Our message to Eritrea is stop the brutality. We're calling on Eritrea to honour the right to freedom of religion, guaranteed under its own constitution."

Eritrean Christians who were tortured and jailed for their faith have told their harrowing stories in the latest edition of Release magazine.

One prisoner, Hzkias, was chained and kept in solitary confinement in a tiny pitch-black cell for five months. He said he "looked like another creature" when he was finally let out, with long hair and nails.

"My body colour was yellow," he said.

A Christian activist documenting persecution in Eritrea, and named in the magazine only as Hanibal, reported that authorities were torturing and killing Christians.

He said: "Christians are treated like animals."

Release is helping Eritrean refugees start their own small businesses, and is supporting churches in refugee camps by giving them Bibles and Christian resources.