During a Sunday service at St Nedelya Church in Sofia, a bomb planted by the Internal Macedonian Revolutionary Organization (IMRO) detonated, leading to one of the deadliest attacks in Bulgaria's history. The IMRO, opposed to the ruling government, sought to disrupt the political status quo and eliminate government officials attending the service. On that day, the church was filled with congregants, including many who were affiliated with the government and military, which heightened the casualties experienced during the assault. The immediate aftermath saw around 150 fatalities and about 500 people suffering injuries, resulting in widespread panic and chaos in Sofia.

In the context of 1920s Bulgaria, this incident is pivotal as it reflects the political unrest and the struggles between various factions vying for power. The assault illustrated the brutal nature of political conflict during this period, with terrorism being used as a method to achieve political ends. The bombings marked a significant increase in political violence that would continue as the country navigated through various social, political, and economic crises over the following decades, including the rise of authoritarianism.

Following the bombing, authorities were forced to respond with heightened security measures and crackdowns on political dissidents. The attack not only shook the citizens of Sofia but reverberated throughout the nation and beyond, emphasizing Bulgaria's precarious political landscape. This tragic incident also prompted an examination of government security measures and responses to terrorist activities, altering the approach to dealing with similar threats in the future.