Tripoli is once again in chaos as militias loyal to Muammar Gaddafi opened fire on protesters as they streamed out of mosques after Friday prayers. Text messages circled around the capital urging residents to return to the streets, which they have been avoiding since the regime launched a brutal, bloody response earlier this week. One Facebook group urging demonstrators to march had over 85,000 members. Marchers left their mosques and converged on Tripoli's Green Square, where they were showered with bullets, killing four. The opposition movement now holds Benghazi, the country's second-largest city, where tens of thousands of people came out to support the first demonstrators in Tripoli in several days. In response, the Gaddafi regime is continuing to dig in: In an interview to be aired on CNNTurk on Friday, Muammar Gaddafi's oldest son, Saif al-Islam, said, "Plan A is to live and die in Libya, Plan B is to live and die in Libya, Plan C is to live and die in Libya."