The comments by Hezbollah's deputy leader Sheik Naim Kassem marked the group's first comment on the nature of last week's explosion, which Israel and UN officials called a violation of a UN Truce resolution.
Resolution 1701, which ended the 2006 war between Israel and Hezbollah, prohibits guerrillas from engaging in military activities in south Lebanon and forbids weapon smuggling to the group. But the guerrillas are believed to continue to have a clandestine presence in the area.
After the explosion in an abandoned building in Khirbet Silim, about 9 miles (15 kilometers) from the Israeli border, Israel accused Iran and Syria of violating those conditions by sending weapons to Hezbollah.
"There is no violation of Resolution 1701," Kassem said. "What happened ... Is a normal incident that has to do with leftover shells that had been collected during and after Israel's withdrawal from Lebanon" in 2000, he said.
Kassem spoke in an interview with the Qatari al-Watan newspaper to be published at a later date. Excerpts of the interview were provided to The Associated Press by Hezbollah's media office Wednesday.
Kassem said Israel exaggerated the Khirbet Silim incident in an attempt to deflect from its occupation as well as its daily violations of Lebanon's airspace.
Last week's explosion was followed few days later by a stone-throwing clash between Hezbollah supporters and UN peacekeepers who were conducting a follow-up investigation to the blast.