At least nine people were killed and thousands of others were injured when handheld pagers exploded across Lebanon on Tuesday in an apparent targeting of Hezbollah members, according to Hezbollah officials.

Lebanon's state-run National News Agency initially reported that "the handheld pagers system was detonated using advanced technology, and dozens of injuries were reported" in Beirut’s southern suburbs and other areas. Lebanon’s health minister later said at least nine people were killed and 2,750 wounded — 200 of them critically.

Among those injured when the pagers exploded included Iran's ambassador in Lebanon, Iranian state media reported.

A security source in Lebanon told Reuters that the pagers were carried by members of Hezbollah. A Hezbollah official, speaking to the outlet on condition of anonymity, described the incident as a detonation that was the "biggest security breach" during the nearly year-long war with Israel. It wasn't immediately clear who was responsible for the attack. While Hezbollah blamed Israel, the Israeli government has not commented.

HEZBOLLAH'S NEIGHBORS: ISRAELI BORDER COMMUNITY UNDER CONSTANT ATTACK FROM TERROR GROUP

Civil Defense first responders carry a wounded man whose handheld pager exploded at al-Zahraa hospital in Beirut, Lebanon, on Tuesday. (AP Photo/Hussein Malla)

Photos and videos from Beirut’s southern suburbs circulating on social media and in local media showed people lying on the pavement with wounds on their hands or near their pants pockets.

"Several hundred" people were wounded in all in different parts of Lebanon when the incident happened, The Associated Press cited a Hezbollah official as saying.

In a statement obtained by Reuters, Hezbollah confirmed that the blasts killed at least two of its fighters and a girl. 

The girl was the 9-year-old daughter of a Hezbollah fighter who was inside her parents' home when the pagers exploded, the Times of Israel reported.

ISRAEL STRUCK BY LONG-RANGE MISSILE FROM YEMEN, 40 PROJECTILES FROM LEBANON IN EARLY MORNING ATTACKS

Hezbollah said the cause of the simultaneous explosions was under investigation.

Hezbollah members recently began using the pagers that exploded after the group's leader ordered them to stop using cell phones over concern that Israeli intelligence could track the devices.

People gather outside the American University hospital after the arrival of several men who were wounded by exploded handheld pagers in Beirut, Lebanon, Tuesday. (AP Photo/Bassam Masri)

Hezbollah is an Islamic terrorist organization that has long had the backing of Iran.

Police officers inspect a car after a hand-held pager exploded inside the vehicle in Beirut, Lebanon, on Tuesday. (AP Photo/Hussein Malla)

The incident comes at a time of heightened tensions between Lebanon and Israel. The Lebanese militant group Hezbollah and Israeli forces have been clashing near-daily for more than 11 months against the backdrop of war between Israel and Hezbollah ally Hamas in Gaza.

CLICK HERE TO GET THE FOX NEWS APP

This is a developing news story; check back for updates.

The Associated Press contributed to this report.