"We are not afraid to say that we had nothing to do with these explosions," Hassan Nasrallah said in a televised address from an undisclosed location in Lebanon, CNN reported.
Israel has blamed Nasrallah's Shiite Muslim group and Iran for the attacks in New Delhi, Tbilisi and Bangkok. The New Delhi attack on an Israeli embassy car wounded the wife of an Israeli diplomat as she traveled to pick up her children from school.
Iran has vigorously denied involvement in any of the attacks.
Nasrallah spoke on the anniversary of the death of Hezbollah commander Imad Mughniyeh in an explosion in 2008 in Damascus. He denied the explosions were meant to avenge the commander's death.
Israel has denied responsibility for Mughniyeh's death.
"The blood of Imad Mughniyeh will always haunt the Israelis," Nasrallah said.
"It is quite insulting to accuse Hezbollah of plans to kill average Israeli civilians in retaliation of killing our leaders," he said. "Those who we will take our revenge from know themselves very well and they will need to keep taking precautions for their safety."
Thai media reports say authorities, who announced Israeli diplomats were the target of the Bangkok attacks, had arrested two people in the attacks. A third was arrested in Malaysia and Thai authorities were looking for a woman in the incident.
Those in custody faced charges including joint assembling of explosive devices, joint possession of explosive devices without permits and causing an explosion injuring other persons, CNN reported.
"I can tell you that the target of the operation of this group is specifically aimed at Israeli diplomats," Police Gen. Priewpan Damapong told CNN affiliate Channel 3.
Separately, a top Thai security official had said the devices used in the Bangkok blasts were similar to those used in New Delhi and Tbilisi.