Police have arrested a 17-year old Pakistani boy for writing an allegedly blasphemous remark in an examination paper, an officer said on Tuesday.Pakistan's blasphemy laws have come under intense scrutiny since the murder last month of a prominent politician who had campaigned to change them. They allow for the death penalty for anyone found guilty of insulting Islam. Critics say they are often used to settle scores and unfairly target the country's non-Muslim minorities.School authorities lodged a police complaint against the boy, identified as Sami Ullah, in January after reading an examination paper he took in the city of Karachi, said police officer Qudrat Shah Lodhi.Lodhi said he could not repeat what the boy, who is a Muslim, had written because he would be committing blasphemy if he did. He said the boy told police he wrote the blasphemous material out of frustration when he was not able to answer the exam question."He submitted an apology to the examination authorities and feels ashamed and depressed," Lodhi saidHe said Ullah was arrested on January 29 and placed in police custody while officers investigated the case.

No one has been put to death for blasphemy, and most times guilty verdicts are overturned on appeal. But there have been several documented cases of mobs killing people accused of blasphemy.Critics have said the laws either need to be repealed or amended to stop them from being abused or applied frivolously. But Pakistan's powerful clerical class have campaigned against any changes, and portrayed critics as being anti-Islam -- a potent charge in this Muslim-majority nation.