Lebanon's Hezbollah group said 20 of its members were killed, with a source close to the group telling AFP on Thursday that they had died in walkie-talkie blasts blamed on Israel the day before.

The group sent separate death notices for each member from Wednesday evening to Thursday morning, saying they had been killed "on the road to Jerusalem" -- the phrase used by Hezbollah to refer to fighters killed by Israel.

"The 20 Hezbollah members were killed by walkie-talkie explosions" across Lebanon on Wednesday, the source told AFP, requesting anonymity to discuss sensitive matters.

Earlier Wednesday, the health ministry said the second wave of explosions of electronic devices in Hezbollah strongholds in Lebanon killed 20 people and left more than 450 people wounded.

Wednesday's blasts came a day after the simultaneous detonation of pagers used by Hezbollah killed 12 people, including two children, and wounded up to 2,800 others across Lebanon, in an unprecedented attack blamed on Israel.

Israel did not comment on the incidents.

Hezbollah chief Hassan Nasrallah is due to give his first televised speech since the attacks on Thursday afternoon.