Egyptian forces flooded smuggling tunnels dug beneath the Gaza-Egypt border, in Rafah in the southern Gaza Strip, on Friday Palestinian witnesses said.
The officials told German news agency DPA that they hope the operation will end smuggling between Egypt and the coastal enclave which is now subject to a blockade.
Abo Mohamed, who refused to divulge his full name, added that Palestinian tunnels’ owners attempted to save dozens of tunnels from collapsing using water suction pumps, but the pumps were not able to handle the large amount of water being pumped.
Gaza, administered by the Islamic Hamas movement, remains under a tight blockade imposed by Israel and Egypt. The Israeli army says the tunnels are used to supply armed factions in Gaza with weapons, and the Egyptians claim they are used by Sinai-based armed groups.
Egypt has destroyed thousands of homes and evicted families from the border, where it is creating a buffer zone.
An Islamist terror group committed to destroying Israel, Hamas has accused Sissi of collaborating with Israel.
The tunnels to Gaza are used to smuggle goods, such as clothing and other products, as well as weapons.
Prior to this, the Egyptian branch of the Islamic State group beheaded a young Croatian who was working for a French company in Sinai. These tunnels were a lifeline for Hamas, which collected millions of dollars in taxes and revenues from the smuggled goods.
However, the violence continued and in July Islamic State-linked militants struck Egyptian army outposts in a series of battles and suicide bombings.