New Delhi, Sept. 18 -- Israeli fighter jets over the Red Sea launched ballistic missiles to target Hamas leaders in Qatar last week, a U.S. defense official said, in what was a novel method likely designed to overcome the energy-rich country's air defenses and avoid entering any Mideast nation's airspace.

The Sept. 9 attack, which killed six people in Qatar's capital, Doha, upended months of diplomacy mediated by the Arabian Peninsula nation to reach a ceasefire in the Israel-Hamas war that has devastated the Gaza Strip over nearly two years. About a week after the missile launch, Israel began a ground offensive targeting Gaza City. That has reignited anger in the region over the war, while the Doha attack has raised fears in other count...