Chechen guerrilla resistance continued, however, and a series of cease-fires were negotiated and violated. In 1996 Dudayev was killed during Russian shelling, and the following year former guerrilla leader Aslan Maskhadov was elected president. Russian Pres. Boris Yeltsin and Maskhadov signed a provisional peace treaty in May 1997 but left the question of Chechnya’s eventual status undetermined. It was estimated that up to 100,000 people in Chechnya died and more than 400,000 were forced to flee their homes during the 1990s.