German airline group Lufthansa said Thursday it was extending a suspension of flights to Tel Aviv, Tehran and Beirut, as regional tensions soared following deadly explosions in Lebanon this week.

"Flights to Tel Aviv and Tehran will be canceled until September 24," Lufthansa said in a statement cited by Agence France-Presse (AFP).

"Flights to Beirut will be suspended until October 26," it added.

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A second deadly wave of unprecedented explosions in the strongholds of Lebanon's Hezbollah left it in disarray on Wednesday, less than 24 hours before an anticipated speech by its Secretary-General Hasan Nasrallah.

The latest batch of device explosions killed 37 people and wounded more than 450 others on Wednesday, officials said today, stoking fears of a full-blown war with “Israel”.

The 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.