In June 1985, Israel withdrew most of its troops from Lebanon, leaving a residual Israeli force and an Israeli-supported militia in southern Lebanon as a "security zone" and buffer against attacks on its northern territory. Since then, the IDF fought for many years against the Shia organization Hezbollah, which became a growing threat to Israel. By July 1985, Israel's inflation, buttressed by complex index linking of salaries, had reached 480% per annum and was the highest in the world. Peres introduced emergency control of prices and cut government expenditure successfully bringing inflation under control. The currency (known as the old Israeli shekel) was replaced and renamed the Israeli new shekel at a rate of 1,000 old shkalim = 1 new shekel. In October 1985, Israel responded to a Palestinian terrorist attack in Cyprus by bombing the PLO headquarters in Tunis. Growing Israeli settlement and continuing occupation of the West Bank and Gaza Strip led to the first Palestinian Intifada (uprising) in 1987, which lasted until the Oslo accords of 1993, despite Israeli attempts to suppress it. Human rights abuses by Israeli troops led a group of Israelis to form B'Tselem, an organization devoted to improving awareness and compliance with human rights requirements in Israel.