Witnesses said the men had been able to communicate with rescuers for the first few days and were fed milk and water through a pipe that had been pushed through the sand.
But since yesterday the men have been silent.
Witnesses said Palestinians had been allowed to cross into the Egyptian side on Saturday to try to help with the rescue process that is under way.
Al Jazeera's Ayman Mohyeldin, reporting from Rafah, said: "There is a great sense of anxiety for the relatives and friends of the diggers that are trapped inside. There is still no word of their condition.
"Palestinian workers tried to reach out to [their] Egyptian counterparts on the other side to get the Egyptian authorities to help with the rescue effort. That process took some time but did manage to get under way."
A tractor trailer on the Egypt side began digging where it is believed the tunnel was and had made "significant progress, but recovery efforts reportedly stopped mid morning", Mohyeldin reported.
"Since the morning, about 300 Palestinian have gathered along the border and Palestinian forces have showed up and tried to push back the crowds.
"It is a bit of a tense situation because last time there was a gathering of such magnitude there was a breach of the border in January 2008 whereby thousands of Palestinians managed to make their way into Egypt to gather critical supplies for several weeks."
Israel says the tunnels are used for smuggling weapons into Gaza and has frequently attacked them with bombs.
But Palestinians say the network of tunnels are a lifeline for them. They are used to smuggle in essential supplies, in short supply in the territory because of a crippling blockade imposed by the Israelis.