Hundreds of pagers exploded simultaneously in Lebanon and Syria on Tuesday in an attack that apparently targeted members of Hezbollah, the Iranian-backed Islamist militant organization and Lebanese political party. It comes amid rising tensions between Hezbollah and Israel as the war in Gaza rages on without any end in sight.

At least nine people were killed, including members of Hezbollah and a child, the AP reported. More than 2,800 were injured, including the Iranian ambassador to Lebanon, with over 200 people in critical condition, according to the Lebanese health ministry. Most of the injuries were hand injuries; hospitals in Beirut have been overwhelmed with patients and are asking the public to donate blood.

Hezbollah officials have blamed Israel for the attack. The Israel Defense Forces (IDF) declined to comment on whether Israeli forces were behind it. Israeli officials did, however, say earlier this week the country could soon escalate its ongoing operations against Hezbollah. Hezbollah is allied with Hamas — the militant group behind the October 7 attack on Israel that sparked the latest war in Gaza — and has grown impatient with stalled ceasefire negotiations over the Palestinian territory, ramping up hostilities and preparing for the possibility of broader war.

The mechanism behind the explosions is unclear. The AP reported that the pagers used lithium batteries and heated up before exploding. Lithium batteries can overheat, catch on fire, and lead to explosions “when they are damaged or improperly used, charged, or stored,” according to the National Fire Prevention Association. Some security experts believe compact bombs were placed in the pagers; Sky News Arabia reported that an explosive heat-sensitive chemical called pentaerythritol tetranitrate (PETN) was put in the pagers and that their battery temperatures were remotely increased, triggering the explosion.

Israel has weaponized personal communications devices against its adversaries in the past. It used an exploding phone to kill a Hamas bomb maker in 1996.

Israel is also known for its sophisticated electronic surveillance capabilities as well as its ability to hack cellphones and computers. Before Tuesday’s attack, Hezbollah commander Fuad Shukr was killed in a July Israeli missile strike after he received a mysterious phone call instructing him to go to the seventh floor of his building in Beirut. After that attack, Hezbollah reportedly stopped using cellphones in favor of pagers and couriers who deliver messages in person; the group has used a private, fixed-line telecommunications network since the early 2000s.

If Israel is behind the pager attack — which was far more extensive and destructive than past attacks harnessing phones — it would demonstrate that Israeli forces have achieved a new level of sophistication in their ability to carry out strikes on enemy soil.

The pager attack could be yet another escalation after months of increasing hostilities between Hezbollah and Israel.

Hezbollah, which is designated as a terrorist organization by many countries and has previously fought wars against Israel, launched its latest campaign after Hamas’s October 7 attack on Israel, saying it was in “solidarity with the victorious Palestinian resistance.” The hostilities have primarily taken the form of airstrikes. It has signaled that it would cease hostilities if a ceasefire in Gaza is reached. More than 41,000 Palestinians have been killed in Gaza.

Almost a year into the war, ceasefire negotiations have made little progress, especially after the recent execution of six hostages in Gaza. It’s an open question whether a deal may even be achievable before US President Joe Biden leaves office. Israeli Prime Minister Benjamin Netanyahu has said that a deal is not close and has resisted international calls for Israeli forces to promise a full withdrawal from Gaza.

As negotiations have stagnated, the conflict between Hezbollah and Israel has deepened, displacing more than 100,000 people who face daily tit-for-tat attacks on both sides of the Lebanese border with Israel. Though it has not yet grown into full-scale regional war, increasingly aggressive tactics on both sides have raised worries that such a conflict may be inevitable.

Intense escalation with Hezbollah, which is considered the most widely armed and powerful militia group in the region, could be catastrophic, as Israel’s previous wars with Hezbollah in 1996 and 2006 would indicate. Both of those conflicts involved heavy civilian casualties in Lebanon, leaving more than 1,200 dead, and led to the killing of about 200 Israelis, mostly soldiers. But Hezbollah now has an extensive rocket and missile arsenal that make it a more formidable foe than it was before. A wider war could also draw each side’s allies further into the conflict — the US on the Israeli side and Iran on Hezbollah’s.

Such a war would also represent a diplomatic failure for the US, which has supported Israel since the beginning of the war in Gaza and played a leading role in the ceasefire negotiations, all with the objective of maintaining stability in the Middle East. Throughout the war in Gaza, US officials like national security adviser Jake Sullivan have repeatedly emphasized that one of the US’s key goals is “to try to keep this conflict that is currently in Israel and Gaza from spinning out into a regional conflict.”

The pager attack may make it harder for Israel and Hezbollah to continue to contain their hostilities and put them one step closer to a full-out war. Both have indicated they are prepared for that possibility.