Hundreds of members of Lebanon's Hezbollah movement, including fighters and medics, were seriously wounded on September 17 when handheld pagers they use to communicate exploded, according to a security source and Lebanon's National News Agency.

The incident, described by a Hezbollah official as the "biggest security breach yet," occurred in the southern suburbs of Beirut, a Hezbollah stronghold, and several other regions in Lebanon.

A Reuters journalist reported seeing at least 10 Hezbollah members bleeding from wounds in southern Beirut. Residents said explosions continued for up to 30 minutes after the initial blasts, causing widespread panic in affected areas.

Lebanon's crisis operations centre called on all medical workers to report to hospitals to cope with the massive influx of wounded, advising against the use of pagers.

Ambulances were seen rushing through Beirut's southern suburbs, while groups gathered to check on potentially wounded individuals.

Regional broadcasters aired CCTV footage showing devices exploding in public areas, including a small handheld device detonating next to a grocery store cashier and another explosion knocking out someone at a fruit stand in a market area.

The explosions come amid heightened tensions between Hezbollah and Israel, who have been engaged in cross-border warfare since October last year. Hezbollah and Israel have been exchanging fire constantly since the October 7 attacks by Hamas gunmen on Israel, while avoiding a major escalation as war rages in Gaza to the south.

There was no immediate comment from the Israeli military in response to Reuters inquiries about the detonations.

The incident has displaced tens of thousands of people from towns and villages on both sides of the Lebanon-Israel border due to ongoing hostilities.