NEW : It urges Israelis , Lebanese `` to exercise maximum restraint '' Israel says rockets fired from Lebanon struck open spaces in northern Israel . There are an estimated 30,000 rockets in southern Lebanon , all under the control of Hezbollah militants . Lebanon says it fired 18 to 12 artillery shells into southern Lebanon in retaliation . There have been no injuries , and no one has claimed responsibility for rocket attack .
NEW : It urges Israelis , Lebanese `` to exercise maximum restraint '' Israel says rockets fired from Lebanon struck open spaces in northern Israel . Lebanon says it fired 18 to 12 artillery shells into southern Lebanon in retaliation . There have been no injuries , and no one has claimed responsibility for rocket attack .