Senior Egyptian officials expressed skepticism Sunday about Hamas claims that the Islamist group would shut down the tunnels connecting Gaza and Sinai if Egypt permanently reopens the Rafah crossing to people and goods.

Cairo ordered the tunnels closed after militants overtook an Egyptian border post in Sinai on August 5, killing 16 Egyptian soldiers and stealing two armored personnel carriers. One of the APCs exploded in the Kerem Shalom border terminal linking Egypt, Gaza and Israel; the other drove two kilometers into Israeli territory before it was hit in an Israel Air Force strike.

The Egyptian officials on Sunday confirmed earlier reports that some of the militants had entered Egypt through tunnels connecting it to the Gaza Strip, and that the Gaza militants, who appear to have been planning to carry out a large-scale terror attack in Israel, were in touch with operatives in Egyptian Rafah.

"We have to resolve the tunnels issue once and for all," one of the Egytian sources said.

The officials said Hamas is in full control of the tunnels, so their assessment is that the movement knew about the attack in advance. However, they said they have not confirmed the identities of all the militants involved in the attack and the matter is still under investigation.

The tunnels were partially active on Sunday, particularly those used for smuggling food. On the Egyptian side, security forces continued to demolish them.

Hamas official official Salah Bardawil said at a press conference in Gaza City Sunday that "neither the Palestinian nor the Egyptian security services have proof that any party in Gaza supported or executed the attack."

"If it is proven that a Palestinian was involved, then measures will be taken," he said, pledging that if there was any evidence against anyone from Gaza, "we will be the first to prosecute the criminals."

Bardawil said reopening the Rafah crossing was "the civilized alternative to tunnels," which are used to smuggle people, weapons and other goods into and out of Gaza.

Bardawil's comments came a day after a leading Palestinian Authority official described the tunnels as a threat to Egyptian security and called for them to be destroyed.

"The tunnels have nothing to do with the economic situation in Gaza," said Tayeb Abdel Rahim, chief of staff to PA President Mahmoud Abbas. He said they should be closed because they "harm the [Palestinian] interests and relations between Palestinians and Egyptians."

"The tunnels have recently become a threat to Egypt's security and to Palestinian unity and they only serve a small category of stakeholders and private interests," he added.

Meanwhile, Egyptian security forces and armed militants in Gaza were engaged in clashes in Sinai, with Arab media reporting that seven gunmen were killed. Early on Sunday, gunmen opened fire on Egyptian soldiers in northeastern Sinai. No casualties were reported in that incident.

AFP contributed to this report.