The Israeli military said the tunnel it destroyed on Monday ran from Khan Younis, in the southern Gaza Strip, into Israeli territory, about 2km (1.2 miles) from the town of Kissufim. The same source reported that nine others were injured, including one that is in critical condition.
But the Hamas military wing said one of its members was killed in a rescue effort.
The Israeli blockade of the occupied Gaza Strip, in its current form, has been in place since June 2007, when Israel imposed an airtight land, sea and air blockade on the area.
But fundamental differences in ideology and practices - such as Hamas' policy of using armed resistance and choosing not to recognise Israel, compared with Fatah, which cooperates with the Israeli occupation - are some of the key obstacles that could undermine the planned unity, as has occurred in the past.
Islamic Jihad spokesman in Gaza Dawood Shihab told reporters "our response to this crime will be taken in the right moment".
ACCUWEATHER ALERT: Heavy rain on Sunday
"Heavy rain will continue in western CT and come to eastern CT over the next several hours", Meteorologist Mike Cameron said. Keep in mind, be watchful of nearby streams and creeks as they will likely crest sometime Monday afternoon/evening.
Israel is building a huge barrier along its border with Gaza aimed at preventing militants tunnelling underneath it. A total of 67 Israeli soldiers and six Israeli civilians were killed in the conflict, while 2,251 Palestinians died, according to the United Nations. The Palestinian enclave is already fenced off above ground.
At the same time, Prime Minister Benyamin Netanyahu received in his office in Jerusalem Donald Trump's Middle East Envoy, Jason Greenblatt and US Ambassador to Israel David Friedman, several days after Netanyahu met with visiting US Treasury Secretary Steven Mnuchin. "Today we detected a tunnel and destroyed it and we will continue to do so".
"The terror organization Hamas is responsible for everything that occurs in the Gaza Strip or emanates from there".
Following the meeting, Mitzna told Israel Broadcast Corporation (Kan) that Abbas has "proven that he is a partner for peace" and said that PA security forces are working diligently to scuttle terror attacks against Israelis in Judea and Samaria.