Some 680 rockets, mortars and long-range missiles were fired at southern Israel in 2011, according to the Israeli military.
On Thursday, the Israel Defense Forces spokesman released the figures compiled by the Home Front Command.
Eighty long-range Grad missiles, which also have a more lethal payload, were fired at Israel in 2011 compared to two the previous year. Five rockets fell on or next to buildings. Nearly one-third of the rockets fell during 15 days.
In addition to the siren early warning system, the Home Front Command is working to implement warning systems using mobile phones, the Internet and television, according to the IDF.