Meanwhile, Abu Sayyaf Group had started out on their own by 1991 under the leadership of the elder Janjalani brother, Abdurajik. By 1995 they had been active in large scale bombings and attacks in the Philippines, and also had become associated with Ramzi Yousef (of the 1993 World Trade Center bombing, the 1994 Philippine Airlines Flight 434 bombing, and the foiled 1995 Operation Bojinka), and also with Jemaah Islamiyah (al-Qaeda's southeast Asia associated branch led by Hambali). At some point in the early 1990s, the younger brother Khadaffy Janjalani had also joined Abu Sayyaf, as a teenager, and was eventually imprisoned by the Philippines government.