According to Maan news agency, five detainees captured Friday morning by the Egyptian army in northern Sinai have been charged of leading “Jihadist” groups and involved in what the Egyptian authorities described as “terrorist attacks” in the Sinai.

Egyptian President Mohamed Morsi has visited the city of el-Arish in North Sinai for the second time since the Sinai attack on Sunday and has vowed to use “a grip of steel to stop the criminals”.

Egypt also temporarily reopened the Rafah crossing into the Gaza Strip, which was shut since the Sinai attack.

 Some 1,500 Palestinians returned to the Gaza Strip on Friday, according to Gaza’s interior ministry.

Maher Abu Sbeiha, director of crossings in the Hamas-run ministry, said that the Rafah crossing would open again Saturday for people traveling into Gaza, but would remain closed to those trying to leave the enclave, Maan new agency reported.

Ismail Haniyeh pledged his support for Egypt’s investigations of the attack, which has led to the biggest Egyptian military assault in the Sinai Peninsula since the October war in 1973.

Hamas has ruled out suggestions that Palestinian gunmen took part in the Sinai killings and has criticized Cairo for imposing “collective punishment” on the impoverished strip by sealing the border.

The Rafah crossing normally sees some 800 people a day leave for Egypt and beyond, according to Reuters. 

Egypt has also moved to seal myriad smuggling tunnels connecting Sinai and the Gaza Strip since Sunday’s attack. the Al-Ahram state-run news website reported on Friday that some 150 tunnels had been destroyed. There are believed to be about 1,000 such tunnels.

Bedouin militants are believed to be behind the attacks of the pipeline which now accounts to 15thsince a popular uprising toppled former president Hosni Mubarak in February 2011, AFP reported.

An official in the company that manages the pipeline said exports of gas to both Israel and Jordan had been halted since an explosion that hit the pipeline in April and that the flames were caused by residual gas, however, residents of El-Arish said gas shipments had resumed three days ago through the pipeline, AFP reported.

Egypt in April canceled its agreement to supply gas to Israel to agree on a new price.

The 2005 Egypt-Israel gas deal has been viewed by many Egyptians with great suspicion while critics point out Israel got gas at below market prices making the deal a rip-off for Egypt.

After the January 2011 uprising that toppled Hosni Mubarak, the deal came under attack from revolutionary groups and critics who said the deal was one of the former president’s worst crimes. The pipeline was bombed by unknown assailants 14 times causing Egypt to halt the deal a month later. Some Mubarak-era ministers and businessmen have faced trial and imprisoned for selling the gas to Israel at so low prices.

No group has claimed responsibility for the attacks yet.