Japan’s Icom Inc., whose brand appears on walkie-talkies that exploded in Lebanon, said it halted production a decade ago of the model allegedly used in the attacks and is still investigating the situation, the Japan Times reported on Thursday.

Icom exported its IC-V82 two-way radio to regions including the Middle East until October 2014, when it stopped making and selling the devices, the Osaka-based company said in a statement Thursday. It has also halted production of the batteries needed to operate the main unit, it said.

Thousands of electronic devices, including pagers and walkie-talkies, exploded over the last two days, killing at least 30 people and wounding more than 3,000. The Lebanese Hezbollah has accused the Israeli government of orchestrating the attacks, with tensions escalating further in the region. Israel has declined to comment.

Among the many outstanding questions is how explosive materials were planted in the devices. If the Icom walkie-talkies were first manufactured a decade ago, it’s possible they were modified well after sale to their original customers. The company can’t determine if the products are their own, it said.

The company said all its radios are manufactured at a factory in Wakayama Prefecture, adding that it follows safety protocols outlined by government regulations and does not outsource production overseas.

Given that photographs of the devices show severe damage around the battery compartment, the batteries may have been modified with explosives after procurement, Icom director Yoshiki Enomoto was quoted as saying in a Kyodo report.

The detonations of everyday electronics may herald a new type of terrorism, according to Mitsuru Fukuda, professor of risk management at Nihon University. "This may increase pressure on companies to expand risk oversight of their supply chains” to include distribution and delivery, he said.