What event signifies the beginning of significant unrest in Libya during the Arab Spring?

The event that signifies the beginning of significant unrest in Libya during the Arab Spring is the violent demonstrations against Muammar Qaddafi. These protests erupted in February 2011, following a wave of uprisings across the Arab world. The demonstrations in Libya were largely fueled by widespread dissatisfaction with Qaddafi's decades-long rule, economic mismanagement, and human rights abuses. The initial peaceful protests quickly escalated into violent clashes as government forces responded with brutal force against demonstrators. This marked the start of a civil conflict that would eventually lead to Qaddafi's downfall.

The other events mentioned, such as international sanctions, announcements of new governments, or protests in neighboring countries, occurred within the broader context of the Arab Spring but did not directly trigger the significant unrest in Libya. The violent demonstrations were the clear catalyst that set off the series of events leading to Libya's tumultuous period during the Arab Spring.