A man who has confessed to killing 100 boys has surrendered to Pakistan's military authorities, police in Lahore have announced.

Javed Iqbal has been the subject of a massive manhunt since detectives reported the activities of potentially Pakistan's worst serial killer.

They were alerted after Iqbal wrote a letter to police in which he confessed to sexually abusing and then murdering the boys, all aged between six and 16 years old.

The letter directed officers to Mr Iqbal's house where they found the pictures and clothes of 100 boys and the remains of two bodies.

Also found were two barrels of acid - allegedly used to dispose of the remains.

Mr Iqbal was seized after walking into the Lahore offices of Pakistan's largest Urdu language newspaper, the Jang, offering to turn himself in.

Jang editor Shaheen Quereshi said Mr Iqbal wanted to write a confession, but was afraid police would try to kill him.

As he began writing, employees alerted Pakistan's military authorities, who sent more than 100 soldiers to surround the building

Widespread unrest

His arrest came only hours after the capture, in the Punjab town of Sohawa, of two alleged accomplices who were trying to cash travellers' cheques belonging to Mr Iqbal.

The case has caused major concern among human rights groups in Pakistan who have launched a campaign to protect the nation's street children.

It has also provoked widespread unrest, with protestors taking to the streets to pressure police into making an arrest.

At one point several police officers were arrested and charged with murdering a key witness in the case.

After Iqbal penned his initial letter of confession, police spent several days interviewing the families of missing children.

More than 80 were identified by relatives who either found their child's picture or recognised clothing from among the piles found in Mr Iqbal's house.