Al-Aqsa television has broadcast a video which it claims shows Hamas militants attacking an Israeli guard post near the border after infiltrating the area through a tunnel.
The video has not been independently verified. The Israeli military had earlier reported Hamas had killed five soldiers near a communal farm.
Tunnels under the border are key in the conflict which is now the longest between Israel and militants from Gaza. They are used to break into their territory say the Israeli Defence Force.
It released footage which it says shows its soldiers discovering a hidden rocket launcher. Israel has vowed to destroy what they say is a sophisticated network of tunnels through its military incursion into Gaza.
Israel stepped up the intensity of its strikes on Tuesday and overnight into Wednesday, saying it had hit a number of tunnels dug by militants to infiltrate and attack Israel.
But the Israeli military said rockets continued to land in Israel from Gaza.
Palestinian officials said Gaza’s port had been destroyed on Tuesday, its only power plant had been put out of action.