The airstrikes came shortly after mortar fire from the Hamas-controlled enclave into Israel. There are no reports of injuries.
"There were seven airstrikes on seven different tunnels," the spokesman said. "On some occasions there were secondary explosions which could prove that there were explosives or munitions inside the tunnels."
The tunnels are used to smuggle arms and other goods into the Gaza Strip. Israel stepped up its blockade of the enclave of 1.5 million after Hamas took control of Gaza in June 2007, ousting the pro-presidential Fatah group.
The attack comes amid efforts by Egypt to broker a permanent ceasefire between Israel and Hamas.
More than 1,300 Palestinians were killed during Israel's three-week military operation in Gaza in December and January, which was launched by Tel Aviv to try and prevent militants firing rockets at southern Israeli towns from the enclave.
