By Camillus Eboh

ABUJA (Reuters) - The main suspect in a Christmas Day bomb attack on a church just outside Nigeria's capital escaped within 24 hours of his arrest, and the police officers involved in the case have been detained pending an investigation, the government said on Wednesday.

Islamist sect Boko Haram claimed responsibility for the bombing of St. Theresa Catholic Church in Madalla, on the outskirts of Abuja, which killed 37 people and wounded 57, the deadliest of a series of a attacks on Christmas.

Police arrested Kabiru Sokoto on Tuesday and while they were taking him from police headquarters to his house in Abaji, just outside Abuja, to conduct a search there, their vehicle came under fire.

"In the course of undertaking this important procedure, the policemen on escort with the suspect were attacked by the suspected sect gang members and in the process the suspect (was) freed," police spokesman Olusola Amore said in a statement.

"The Police view this development as a serious negligence on the part of the Commissioner of Police and have since queried and suspended him from duty," he said.

The inspector general of police, Hafiz Ringim, has been called in to explain "within 24 hours" the circumstances that led to the suspect's escape, the minister for police, Captain Caleb Olubolade, told journalists.

"If he is found guilty of complicity, he himself will have to account for his mistakes," he said, adding: "I have also directed that the officers involved and the personnel involved should be detained immediately."

Last year was the second in a row that Boko Haram has attacked churches at Christmas. Its strikes are becoming deadlier and more sophisticated, and have raised fears that the militants are trying to ignite sectarian strife between Nigeria's largely Muslim north and Christian south.

Boko Haram, meaning "Western education is sinful" in Hausa, has also been blamed for a campaign of shootings and bombings against security forces and authorities in the north.

Attacks in and around the capital - including one on the U.N. headquarters in August that killed at least 24 people - suggest the group is trying to raise its profile and radiate out from its heartland in the northeast.

(Additional reporting by Felix Onuah; Writing by Tim Cocks; Editing by Peter Graff)