Head of Hamas' politburo Sheikh Ismail Haniyeh said Friday the group was developing their military capabilities and were rebuilding tunnels in preparation of a future conflict with Israel.

Haniyeh made the comments as part of his weekly sermon at the end of Friday prayers in Gaza and ahead of a funeral for seven members of the organizations killed this week during a tunneling accident in the northern part of the Strip.

Open gallery view Palestinian militants pray by the bodies of seven Hamas member killed repairing a tunnel during their funeral at a mosque in Gaza City, Friday, Jan. 29, Credit: Reuters

"There are those who think that the calm is a time of rest," Haniyeh said. "But this is a continuation of the struggle. Al-Aqsa Martyrs’ Brigades are working and preparing for Palestine. Fighters are digging twice as much as the number of tunnels dug in Vietnam," he said.

"In east Gaza there are heroes digging tunnels under the ground and in the west there are those testing rockets. The Al-Aqsa Martyrs’ Brigades are digging tunnels to defend Gaza and turn it into a launch pad for all of Palestine," Haniyeh added.

He also praised Gaza steadfastness "thanks to the patience of the Strip's residents and despite the siege and war and schemes against Gaza. I tell all those who are doubtful at our resilience: forgo this logic. We are prepared to go without bread and without water, but we will not live without respect."

During the last conflict between Israel and Gaza militants, Operation Protective Edge in 2014, Israel unearthed 32 offensive tunnels dug by Palestinians into Israeli territory; roughly a third have since been reconstructed in eastern Gaza, reaching into Israel. The Israel Defense Forces have destroyed many of them, but Hamas is investing serious efforts in renewing them.