An Egyptian security official has denied media reports that a deal was made with jihadists to secure the release of seven hostages in the Sinai Peninsula.

Some media reports claimed Egyptian authorities had agreed to free 18 jailed jihadists in exchange for the hostages, Al-Ahram Arabic news website reported on Wednesday.

Seven security personnel were held captive in the Sinai Peninsula for almost a week before being released on Wednesday as preparations for a rescue operation by the army were underway.

The kidnappers had earlier demanded the release of a number of detained jihadists, including Ahmed Abu-Shita, who was sentenced to death in September for involvement in attacks on an Al-Arish city police station and a bank in 2011, in which five security officers and one civilian died.

An anonymous government official said on Wednesday that the kidnapping was an "unplanned action" by Sinai residents in protest at the alleged torture of Abu-Shita by police.

Other security sources said the abductors released the men because they feared a confrontation with the army, and on condition that they would not be harmed.

Militants have launched a number of attacks on targets in Israel and the peninsula since Egypt's revolution began in January 2011.

The Egyptian army announced on Wednesday that it had launched operations to cleanse North Sinai of terrorist groups and militants.