From 1844 to 1848, tension between Babis and the rest of the population increased rapidly through several key incidents: the arrest and trial in Baghdad of the Bāb’s emissary, Mollā ʿAlī Besṭāmī in 1260/1844-45; the arrest and punishment of three Babis in Shiraz in 1261/1845; the arrest of the Bāb on his return from the ḥajj in the same year; several challenges to mobāhala (mutual imprecation) issued by the Bāb and his followers to ʿolamāʾ in Iraq and Iran in 1262/1846 and 1263/1847; attacks on individual Babis in Hamadān, Qazvīn, Karbalāʾ, and Kermānšāh during the same period; and attacks on Babi merchants and ʿolamāʾ in Qazvīn in 1263/1847, leading to the assassination by three Babis of Mollā Moḥammad-Taqī Baraḡānī in October of that year. (For details of these incidents, see MacEoin, “Holy War,” pp. 109-12).

Several sources indicate that Babis in different centers were collecting and manufacturing arms in readiness for the postponed ḵorūj on the imam’s appearance (ibid., pp. 111-12; Māzandarānī, Ẓohūr al-ḥaqq, p. 374). The first serious incidents occurred in 1264/1848 in Mašhad, where armed members of the large Babi community clashed on two occasions with local soldiery. Expelled from Mašhad in Šaʿbān, 1264/July, 1848, a party of Babis under the leadership of Mollā Moḥammad-Ḥosayn Bošrūʾī headed into Māzandarān and in October of that year established themselves near Bārforūšī at the shrine of Shaikh Abū ʿAlī al-Fażl Ṭabarsī, which they fortified. From an original total of about 300, the number of insurgents rose to between 540 and 600 (Momen, “Social Basis,” pp. 161-65, esp. table 4). Leadership of the fort was in the hands of Bošrūʾī and another of the Bāb’s original disciples, Mollā Moḥammad-ʿAlī Bārforūšī Qoddūs. Between 14 Ḏu’l-qaʿda 1264/13 October 1848 and 16 Jomādā II 1265/9 May 1849, the Babi defenders and state troops under the overall command of Mahdīqolī Mīrzā engaged in sporadic fighting, with heavy losses of life on both sides. The siege was finally ended by a ruse and the surviving Babis either executed or taken prisoner.

Following disturbances in Yazd, a prominent Babi ʿālem (scholar) named Sayyed Yaḥyā Dārābī Waḥīd moved to Neyrīz in Rajab, 1266/May, 1850; on his arrival he preached to large crowds and soon converted (or at least gained the support of) a sizeable part of the population of the Čenārsūḵta quarter. Existing tensions between the populace and the governor, Zayn-al-ʿĀbedīn Khan, seem to have been reformulated and exacerbated by Dārābī, who was regarded by his followers as an independent authority in the town. Fighting soon broke out, whereupon around 1,000 Babis occupied the fort of Ḵᵛāja outside Neyrīz, where they were besieged by troops sent by Fīrūz Mīrzā Noṣrat-al-Dawla, the governor of Fārs. Hostilities continued until the capture of the fort by treachery in Šaʿbān/June; about 500 Babis were killed during the fighting and in the executions that followed.

The Zanjān episode of 1266-67/1850-51 was the most protracted and involved the largest numbers, with the town almost equally divided between the Babis and their opponents. The former, numbering over 2,000, were led by Mollā Moḥammad-ʿAlī Zanjānī Ḥojjat-al-Eslām, a former Aḵbārī ʿālem who had already been the center of religious controversy before his conversion and who seems to have advocated radical social changes. In the course of heavy fighting between the Babis and several contingents of state troops, from 1,000 to 1,800 Babis lost their lives and parts of the town were badly damaged.