Hizbollah was reeling on Wednesday from twin co-ordinated attacks suspected to have been carried out by Israel that detonated thousands of electronic devices, causing mayhem across Lebanon in a humiliating blow to a force once seen as impregnable.

A day after the initial attack that killed 12 people and injured thousands, the group — also the dominant political force in Lebanon — was still grappling with the implications of the unprecedented assault when a second round of blasts hit, this time from walkie-talkies and other devices.

The detonations have embarrassed the powerful militant group in front of its supporters and a nation weary from nearly a year of a war of attrition with Israel. At the same time, the explosions left the militant group contending with badly reduced access to key communication channels at a critical time.