Deadly suicide blast kills three at army site in Egypt

At least four soldiers have been killed and 15 others injured in car bomb explosions at an intelligence facility in Rafah in Egypt's Sinai, witnesses told Al Jazeera.

Two cars driven by suicide attackers drove into the outside gates of the military intelligence service building in the Imam Ali area in Rafah on Wednesday, witnesses said. One of the cars exploded at the checkpoint outside the building, the other one exploded farther inside.

Witnesses said the powerful blasts shattered the windows of other buildings in the Imam Ali area.

The attacks come just days after an al-Qaeda-inspired group in the peninsula claimed credit for a Cairo bombing that targeted the interior minister last week. The group also pledged more attacks.

The military has poued troops and armor into Sinai to crush an uprising that surged after the army overthrew Islamist President Mohamed Morsi on July 3.

A subsequent crackdown on armed groups by authorities left hundreds dead.

In its statement, the Ansar Beit al-Maqdis group -- Partisans of Jerusalem in English -- had blamed interior minister Mohammed Ibrahim and army chief Abdel Fattah al-Sisi for the killings of hundreds of Morsi's supporters.

"We call on all Muslims in Egypt to stay away from all military and interior ministry installations to preserve their lives," the group said.

The Egyptian army has been collapsing tunnels between Gaza and Egypt and demolishing homes in Rafah in recent days as part of a plan to stem the flow of smuggled weapons and goods between the strip and Egypt.

Battles have also intensified between armed groups in the Sinai and Egyptian military forces.

Al Jazeera and wire services