The Jerusalem Post reported:
At the same event, former US president Bill Clinton warned of the dangers of a proliferation of dirty bombs, noting that the kind of bomb that was used to kill 168 people at the Federal Building in Oklahoma City in 1995, if combined with fissile material, would "take out 20% of Washington."
It's not clear at which event Clinton made his dirty bomb remarks. The article mentions several:
P5 +1 meetings on Iran held in BrusselsBill Clinton talking "dirty" isn't a surprise. Why would an Israeli paper be the sole quoter?
Obama's Asian trip
Site of Netanyahu's remarks earlier this week