Explosives were not used to destroy the latest tunnel and no deaths were reported.
The Israeli military has destroyed this weekened an attack tunnel reaching from the Gaza Strip into Israeli territory.
"The continuation of the instances of [rocket] fire will lead to a severe and painful response by the Israel Defense Forces".
He said the tunnel was not complete, but was "very substantial", equipped with electricity, communications equipment and a ventilation system. While the existence of the tunnel was revealed on Sunday it had been discovered earlier, the miltiary said. A network of Gaza tunnels allowed Hamas gunmen to blindside Israel's superior forces during the 2014 war and the Israelis, with United States help, have since stepped up work on counter-measures.More news: Rights group calls for new NPA to be of 'unimpeachable integrity'
"We monitored this tunnel for a long period of time", he said.
The Salafi Islamic terror group Tawhid al-Jihad, which has in the past sought to overthrow Hamas's rule in Gaza, later claimed responsibility for the rocket launches. It added that Hamas is the authority governing the Gaza Strip and as such is responsible for everything happening there.
It is the second terror tunnel neutralized in recent weeks.
The statement from the terror group did not explicitly reference the attack tunnel destroyed over the weekend by the Israeli army.