Israeli warplanes attacked Beirut's southern suburbs at daybreak Monday, renewing bombardment of the Hizbullah stronghold a day after guerrilla rockets killed 15 Israelis in northern Israel. The sound of four loud explosions in a spate of 20 minutes from the southern suburbs and the roar of raiding jets shook the Lebanese capital. The missiles kicked up smoke and dust in the sky. It was not clear what was hit in the four airstrikes. South Beirut also was targeted by Israeli warplanes Sunday afternoon.