The confession of a Pakistani teenager who was captured moments before carrying out a suicide attack has given police a rare glimpse into a militant network they say is behind the recent surge in sectarian violence.

Usman's testimony, a copy of which has been seen by Reuters, describes a web of radical seminaries and training and bomb making facilities stretching from eastern Afghanistan, where the young man was recruited, to Pakistan's southern Sindh province.

Hundreds of people have been killed in attacks on Pakistan's small Shi'ite community, heightening fears in the Sunni-dominated country of an escalation in sectarian bloodshed that has been a persistent threat for decades.

Pakistani police believe the network, which Usman says aided him on his 2,000 km journey, has also helped Islamic State spread its extremist agenda in South Asia, even without proven operational links with its core in the Middle East.

Read more:  Reuters