Taiwan investigators searched four locations on Thursday as part of a probe into the origin of pagers that exploded while being used by Hezbollah operatives in Lebanon, authorities said.

The deadly simultaneous explosions triggered by hundreds of pagers carried by Hezbollah members in Lebanon have thrust a little-known Taiwanese electronics manufacturer into the global spotlight, after its damaged products were identified in images following the attack.

The company, Gold Apollo, said it had not manufactured the devices, pointing to another company that it said was licensed to use its brand.

China has announced sanctions on American companies selling arms to the self-ruled island of Taiwan, which Beijing claims as its own territory and threatens to annex by force.