In a stunning escalation, Hezbollah launched a barrage of retaliatory rockets at Israeli military command centers and illegal settlements following deadly airstrikes in Beirut that left at least nine dead and dozens wounded.

At least 31 people, including three children, were killed in Friday's strike, Lebanese officials said. Israel's military said a top Hezbollah commander was among the dead.

By Jonathan Saul, Steven Scheer and Ari Rabinovitch LONDON/JERUSALEM (Reuters) - The mass pager attack against Hezbollah in Lebanon has turned the spotlight on Israel's secretive Unit 8200, the Israel Defense Forces' intelligence unit,