At least nine people were killed and more than 2,750 injured on Tuesday after pagers belonging to a large number of employees of various Hezbollah units and institutions exploded, according to Lebanese officials and the terror organization.

Hezbollah blamed Israel for the attack and vowed to respond. The apparent attack comes amid rising tensions between Israel and Hezbollah.

“We hold the Israeli enemy fully responsible for this criminal aggression, which also targeted civilians and led to the death of a number of martyrs and the wounding of a large number with various wounds,” Hezbollah said in a statement. “This treacherous and criminal enemy will certainly receive his just punishment for this sinful aggression, whether he expects it or not.”

The dead and wounded included people who are not members of Hezbollah, such as a 10-year-old girl who was killed in the eastern village of Saraain, according to Hezbollah-owned Al-Ahed News. Two Hezbollah members were also dead, the outlet reported.

“These explosions, the causes of which are still unknown, led to the martyrdom of a girl and two brothers, and to the wounding of a large number of people with various injuries,” Hezbollah said in a statement.

About 200 of the injuries were serious, meaning they required surgery, Lebanon’s Health Ministry said. Most of the wounds were to the face, hand or abdomen, officials said.

Iran’s ambassador to Lebanon, Mojtaba Amani, was among those carrying a pager and was injured in an explosion on Tuesday, Iranian state television reported.

According to Iranian state television, Amani said in a telephone conversation after the incident that he felt “good and fully conscious.”

The Lebanese Ministry of Foreign Affairs and Foreign Affairs has said it condemns the alleged Israeli attack and has begun preparing a complaint to the Security Council.

The Lebanese Council of Ministers jointly condemned “this criminal Israeli aggression, which constitutes a serious violation of Lebanese sovereignty and a crime by all standards,” adding that “the government has immediately established all necessary contacts with the countries concerned and the United Nations to assume its responsibility for this ongoing crime.”

Hezbollah said it is conducting a “security and scientific investigation to determine the causes that led to these simultaneous explosions.”

According to a US official, there have also been high-level contacts between the US and Israel following Tuesday’s incidents in Lebanon.

The U.S. said it had no role in the apparent attack on Hezbollah and no warning that it would happen, according to State Department spokesman Matthew Miller. He also declined to provide an assessment of who might be behind it, saying only that the administration was “gathering information” about the incident.

Miller would not say whether the administration had information to cast doubt on Hezbollah’s claim that Israel was behind the explosions, saying only that he would not make “any assessment.” The Israeli government declined to comment on the matter.

According to press secretary Karine Jean-Pierre, the White House said it was not aware the attack was happening and did not want to speculate about who was behind it.

The strike comes as U.S. diplomats scramble to prevent escalation on Israel’s northern border and amid fears that a full-fledged war between the country and Hezbollah, which is sitting on a massive missile base, could engulf the region. Secretary of State Antony Blinken happens to be en route to the region and is scheduled to land in Egypt on Tuesday night.

US Defense Secretary Lloyd Austin and Israeli Defense Minister Yoav Gallant spoke again on Tuesday after meeting on Monday.

According to Pentagon spokesman Maj. Gen. Pat Ryder, the latest conversation was intended to “address the ongoing tensions in the Middle East and the threats facing Israel, including the Houthi missile attack last weekend.

Ryder said the US wants to focus primarily on preventing tensions in the region from escalating.

“We are convinced that diplomacy is the way to reduce tensions along the Israel-Lebanon border,” he said.

Iran and Hezbollah are likely to retaliate for the attack, but it may take some time before they do so as they assess what happened, a U.S. official said. The official also said that 50 or more people in Syria were targeted in the attack.

The Lebanese Ministry of Health issued a statement on Tuesday calling on all hospitals in different regions of Lebanon to be on maximum alert and increase their readiness to meet the urgent need for emergency medical services.

The ministry noted that preliminary information indicates that “the injuries were related to the explosion of wireless devices in the possession of the injured.”

The ministry also asks all citizens who own beepers to dispose of them immediately.

The Lebanese Red Cross said it had deployed “more than 30 ambulances” to assist in the treatment and evacuation of “those injured as a result of the multiple explosions in the south, the Bekaa and the southern suburbs of Beirut,” according to a post on the Red Cross’s official X account.

The group added that “50 additional ambulances and 300 paramedics are on standby to assist in the evacuation of victims.”

According to the Lebanese Ministry of Health, about 100 hospitals have admitted the wounded.

In February, Hezbollah leader Hassan Nasrallah had called on his members to stop using mobile phones, saying: “I call for the abolition of mobile phones at this time, because they are considered deadly.”

ABC News’ Luis Martinez, Shannon K. Kingston and Anne Flaherty contributed to this report.