Israeli authorities say the denied Red Cross permission to search for survivors
Palestinian militants say five more dead in tunnel blown up by Israel
A Palestinian militant group announced on Friday another five fighters had been killed when Israel blew up a tunnel from the Gaza Strip, bringing the total number of dead to 12.
Islamic Jihad said five more men trapped in the tunnel were dead, naming them. Israel had on Monday carried out a "controlled" explosion on the tunnel crossing the border.
"We announce the death of five new heroes of the Jerusalem Brigades in Zionist bombing," Islamic Jihad said, referring to its military wing.
Two of the 12 dead belonged to the militant wing of Hamas, the Islamist group that controls Gaza, with the other 10 from Islamic Jihad.
Since Monday's explosion, Israel has refused to allow the Palestinian Civil Defence Authority access to the site to search for survivors.
The International Committee of the Red Cross had asked Israel to enable searches in the tunnel, according to a statement on Thursday from Cogat, the Israeli defence ministry unit which liaises with the Palestinian territories.
Cogat commander Yoav Mordechai told the head of ICRC in Israel that the Israeli authorities would "not enable searches in the security perimeter in the Gaza Strip, without progress on the issue of the Israeli captives and missing soldiers".
The destruction of the tunnel network created by Hamas was a key objective in Israel's most recent war on Gaza in 2014, and discoveries of new tunnels have since been rare.
The two sides have fought three wars since 2008. Israel maintains a crippling blockade of Gaza which it says is necessary to deny Hamas access to materials for building weapons and tunnels.