Hundreds of pagers have exploded simultaneously across Lebanon and in parts of Syria, killing at least eight people, including members of the militant group Hezbollah and wounding the Iranian ambassador, officials said.

Officials pointed the finger at Israel in what appeared to be a sophisticated, remote attack that wounded more than 2,700 people at a time of rising tensions across the Lebanon border.

The Israeli military declined to comment.

A Hezbollah official who spoke on condition of anonymity told The Associated Press that the new brand of handheld pagers used by the group first heated up, then exploded, killing at least two of its members and wounding others.

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Lebanon’s health minister, Firas Abiad, said at least eight people were killed and 2,750 wounded — 200 of them critically.

Iranian state-run IRNA news agency said that the country’s ambassador, Mojtaba Amani, was superficially wounded by an exploding pager and was being treated at a hospital.

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.

Hezbollah leader Hassan Nasrallah previously warned the group’s members not to carry mobile phones, saying that they could be used by Israel to track their movements and to carry out targeted strikes.

Lebanon’s Health Ministry called on all hospitals to be on alert to take in emergency patients and for people who own pagers to get away from them. It also asked health workers to avoid using wireless devices.

AP photographers at area hospitals said the emergency rooms were overloaded with patients, many of them with injuries to their limbs, some in serious condition.

The state-run National News Agency said hospitals in southern Lebanon, the eastern Bekaa Valley and Beirut’s southern suburbs — all areas where Hezbollah has a strong presence — had called on people to donate blood of all types.

The news agency reported that in Beirut’s southern suburbs and other areas “the handheld pagers system was detonated using advanced technology, and dozens of injuries were reported”.

The Hezbollah official who spoke on condition of anonymity because he was not authorised to speak to the media said the explosions were the result of “a security operation that targeted the devices.”

“The enemy (Israel) stands behind this security incident,” the official said, without elaborating. He added that the new pagers that Hezbollah members were carrying had lithium batteries that apparently exploded.

Lithium batteries, when overheated, can smoke, melt and even catch on fire. Rechargeable lithium batteries are used in consumer products ranging from phones and laptops to electric cars. Lithium battery fires can burn up to 590C.

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.

The clashes have killed hundreds in Lebanon and dozens in Israel and displaced tens of thousands on both sides of the border. On Tuesday, Israel said that halting Hezbollah’s attacks in the north to allow residents to return to their homes is now an official war goal.

Israel has killed Hamas militants in the past with booby trapped cellphones and it’s widely believed to have been behind the Stuxnet computer virus attack on Iran’s nuclear programme in 2010.