A British-born Boko Haram chief accused of plotting deadly terrorist attacks was radicalised while at university in the UK.

Aminu Sadiq Ogwuche, 29, was arrested on Wednesday for allegedly masterminding Boko Haram bomb attacks in the Nigerian capital Abuja that killed nearly 100 people.

Ogwuche, the son of a retired Nigerian army colonel, was a student at the University of Glamorgan, in south Wales, where he studied business science from 2007, until he dropped out in 2010.

While at university, Ogwuche called himself "The Lion of God", in a series of increasingly extreme postings on Facebook in which he vowed to cut off the hands and feet of non-believers.

"The only punishment of those who wage war against Allah and His Messenger and strive to make mischief in the land is that they should be murdered, or crucified, or their hands and their feet should be cut off, or they should be imprisoned," he wrote in 2010.

He was arrested by Nigerian authorities after his return to the country following a reported tip-off from British intelligence, but was released following a campaign by human rights groups and his family.

He fled to Sudan, but was implicated in co-planning the bombings in an Abuja suburb, the first of which happened the same day as the group seized 200 schoolgirls in the conflict-ravaged north of the country early in May.

He was arrested this week after a chance sighting by a former military school classmate who spotted him in Sudan. Ogwuche is a former lance corporal with Nigerian military intelligence and deserted in 2007.

University friends told WalesOnline that they were shocked at reports that he had turned to violent radicalism.

Former housemate Anju Moro said: "He was very devout but then many people are. He would often just spend time in his room between going to and from prayers but he seemed harmless, if very serious. It is very creepy that he could have been having thoughts like that."

A spokeswoman for the University of South Wales said that there was "no evidence of any radical behaviour" while he was at the university.

"The university has a strong community ethos with no history or evidence of extremist behaviour across any of its campuses so it is surprised to hear of his apparent involvement with terrorist group Boko Haram," it said in a statement. "There were no reported indications of extremist behaviour during his time as a student. There has been no contact between Ogwuche and the university following his departure in 2010."