Egypt on Thursday inaugurates a "new Suez Canal" waterway touted as an achievement rivaling the digging of the original, as it seeks to boost both its economy and international standing.

The ceremony, to be attended by foreign dignitaries including French President Francois Hollande, comes just over two years after President Abdel Fattah al-Sisi, the former military chief, overthrew his Islamist predecessor.

Four Egyptian warships entered the Suez Canal on Thursday en route to the Gulf of Aden after Egypt pledged military support for a Saudi-led campaign against rebels in Yemen, canal officials said.

The officials said the ships will take part in operations "to secure" the strategic waters that control southern access to the Suez Canal.

Egypt plans to build a new administrative and business capital east of Cairo that will house five million people and feature a theme park "four times bigger than Disneyland", a minister announced at a global investor conference.

Housing Minister Mustafa Kamel Madbuli said the new city would relieve pressure on overcrowded Cairo, with its population of 18 million expected to double in coming decades.

Suspected militants blew up a gas pipeline in Egypt's Sinai peninsula on Tuesday and gunmen shot dead a policeman in the Suez canal city of Ismailia, security officials said.

Attacks in the Sinai and violence targeting soldiers and policemen across Egypt have surged since the military's overthrow of Islamist president Mohamed Morsi in July.

Security forces defused a bomb placed in a car and primed to explode on a roadside near the Egyptian capital on Monday, security officials said.

The interior ministry said the stolen car was detected near a petrol station on the road to the city of Suez.

Iran plans to dispatch a small naval fleet to the Mediterranean in line with its intention of boosting its presence in international waters, its navy chief was cited by the media Thursday as saying.

The deployment will mark Iran's third mission since the 1979 Islamic revolution to the Mediterranean. Iranian warships docked at Syrian ports in 2011 and 2012.

Two Iranian warships sent by Tehran to the Mediterranean last week to help "train the Syrian navy" entered the Suez canal early on Tuesday on their way back to Iran, a canal authorities source told Agence France Presse.

The ships, a destroyer and supply vessel, came from the Syrian port of Tartus and were heading south towards the Red Sea, the source said, adding that they were due to complete their transit of the canal by Tuesday afternoon.

Hundreds of people torched police cars and tried to storm government buildings in the Egyptian city of Suez on Wednesday, after a court confirmed the bail of police accused of murdering protesters.

Witnesses said angry people took to the streets of the canal city, burning police cars, pelting government buildings with stones and some trying to storm security headquarters.

Two Iranian warships that have sailed from the Suez Canal into the Mediterranean are carrying advanced missiles to Hizbullah, Israeli sources told Maariv daily.

The sources said in remarks published in the Israeli daily that the warships are carrying missiles, arms, ammunition and night-vision goggles to Hizbullah in Lebanon.

Iran is sending two warships into the Mediterranean Sea, Israel's foreign minister said Wednesday, labeling the act a "provocation" the Jewish state cannot ignore for long.

"Tonight two Iranian warships are supposed to cross the Suez Canal into the Mediterranean Sea on their way to Syria," Foreign Minister Avigdor Lieberman said, speaking at a conference of American Jewish leaders in Jerusalem.