The Russians, fearing the effect of Babi propaganda near their border

After having been protected at Isfahan, in 1847 the Bab was imprisoned in Sunni Kurdistan where he continued to spread his predictions of catastrophe via his disciples. The Russians, fearing the effect of Babi propaganda near their border – they already had faced two Messianic preachers in the Caucasus – demanded that the prisoner be moved away from their territories. The Bab was thus taken to the Ottoman border to the Chehriq fortress, but still numerous visitors came to see him. As the agitation continued, Mirza Aqasi decided to have him judged at Tabriz to humiliate him in front of his followers when he continued to claim to be the Twelfth Imam. Despite the determination of the ulama who interrogated him and judged him to be guilty of apostasy, he was declared insane and got away with a bastinado. At the same time, the Babis rose up in the north of the country, notably around the stronghold of Sheykh-Tabarsi in Mazandaran. After a ten-month siege they surrendered; the survivors were disemboweled and had their throats slit. But the Bab, although better supervised in the fort where he had been taken after his trial in Tabriz, continued to make himself heard by visitors to whom he spoke via his prison’s window. He was still there when the Shah died.

(Iran - A Social and Political History since the Qajars, Yann Richard, Sorbonne Nouvelle – Paris, Cambridge University Press, p. 33)