A boy holds a cross during the "Coca" celebration in Redondela, rural northeastern Spain June 18, 2006. REUTERS/Miguel Vidal

LONDON (Reuters) - A British bishop was arrested on suspicion of child cruelty after he helped his two young sons to perch on top of the chimney of their house to read a book as part of a school project.

Bishop Jonathan Blake, of the Open Episcopal Church, took pictures of his sons Nathan, eight, and Dominic, seven, while they sat on top of their two-storey home.

The children were calmly holding a book called “The Killer Underpants” for a school competition to find the most unusual place where a pupil had read a book.

After a neighbor alerted the police, the clergyman said he was arrested, driven away in a cage in the back of a van and kept overnight in a cell.

“I was taken out in handcuffs in front of the whole neighborhood while my children were in tears,” the 52-year-old told Reuters on Thursday. “I was kept in the cells without any information about what was taking place from 7 p.m. until 10 a.m. the following morning.

“I am appalled and incredulous. I would never have imagined in a thousand years that this could have happened.” The children were wearing safety harnesses and got on to the chimney via a flat roof at the back of the house in Welling, southeast London, he added.

Blake said he would make an official complaint and has already contacted London police chief Paul Stephenson and Mayor of London Boris Johnson.

A Metropolitan Police spokesman said: “A member of the public reported that two small children had been left unattended on the roof of a house. A 52-year-old man was arrested in connection with the allegation and has since been released without charge.”