A teenager and two other men were convicted Monday of possessing documents useful to terrorists. They are to be sentenced Tuesday.

The prosecution said the two older men had computer files promoting violent jihad, documents with practical information on making and using weapons and explosives, and one that urged assassinations.

A jury at Blackfriars Crown Court convicted Hammaad Munshi, 18, of having a guide to making napalm. He is the youngest person convicted of a terrorist offense in Britain, the Crown Prosecution Service said.

Aabid Khan and Sultan Muhammad, both 23, were convicted of possessing documents useful to terrorists.

A fourth man, Ahmed Sulieman, 30, was found innocent.

Judge Timothy Pontius deferred sentencing until Tuesday, but said all three convicted men were likely to draw prison sentences.

Prosecutors said Khan had recruited Munshi, who was 16 at the time of his arrest and that Munshi wrote notes about martyrdom and hid them under his bed.

Prosecutors said Khan had links with proscribed terrorist organizations and helped radicalize jailed “wannabe suicide bomber” Mohammed Atif Siddique. Siddique was found guilty last year in a trial in Scotland of four terrorism offenses.

Khan, who was arrested in 2006 after a four-month trip to Pakistan, testified that his interest in violent jihad began at age 12.

“I felt upset and angry with the onslaught against innocent women and children in countries such as Russia,” he testified.

Prosecutor Simon Dennison said thousands of computer files on a hard-drive and some DVDs in Khan’s suitcase demonstrated “deep commitment to and involvement in violent jihad by promoting it, inciting others to take part in it and arranging for himself and others to attend military training in Pakistan in preparation for going to fight and, inevitably, to kill.”

He said one document urged “assassinating named personnel and foreign tourists, and freeing captured brothers from the enemy,” Dennison said.

Muhammad had similar material, the prosecutor said.