Hundreds of pagers carried by Hezbollah members exploded simultaneously across Lebanon on Tuesday, a day after Israeli officials said they were ready to step up attacks against the Iranian-backed militia.

The pagers exploded on sidewalks and in grocery stores, at homes and inside cars, killing at least 11 people and wounding at least 2,700 others, officials said. Witnesses reported smoke coming from pants pockets before loud bangs knocked people off their feet. Hezbollah said at least eight of its fighters had been killed.

Lebanon’s health minister, Firass Abiad, said that one of those killed was an 8-year-old girl and that many victims had maimed hands and injured eyes. The health ministry put hospitals on “maximum alert,” and asked citizens to throw out their pagers. Hezbollah said at least six of its fighters had been killed.

Hezbollah has used pagers for years to make it harder for messages to be intercepted. At 3:30 p.m., the pagers received a message that appeared as though it was coming from Hezbollah’s leadership, according to two officials familiar with the attack. The pagers beeped for several seconds before exploding.

The blasts appeared to be the latest salvo in a conflict between Israel and Hezbollah that escalated after Hamas attacked Israel on Oct. 7, and Hezbollah, its ally, began firing rockets into northern Israel in support. Both militant groups are backed by Iran.