By Yasmine Saleh
CAIRO (Reuters) - The Sinai-based Islamist militant group Ansar Bayt al-Maqdis claimed responsibility on Sunday for an attempt last week to kill the Egyptian interior minister in Cairo, and promised more attacks in revenge for a crackdown on Egypt's Islamists.
Islamist militancy has risen sharply in the relatively lawless region adjoining Israel and the Gaza Strip and elsewhere in Egypt since the army deposed Islamist president Mohamed Mursi two months ago, following mass protests.
Thursday's daylight attack was easily the most spectacular so far, as a suicide car bomber blew himself up next to Interior Minister Mohamed Ibrahim's convoy as he left his Cairo home for work in an armoured limousine. The bomber, a passer-by and an unidentified person were killed and more than 20 wounded.
"God allowed us to break the security system of the minister of interior ... through a suicide operation committed by one of Egypt's lions that made the interior butcher see death with his eyes, and what is to come will be worse," the group said on Sunday in a statement posted on a jihadist website.
Last year the same group, whose name means "Supporters of Jerusalem", claimed responsibility for rocket attacks launched on Israel from Sinai.
It has also claimed at least 10 attacks in the past two years on a gas pipeline linking Egypt, Israel and Jordan.
On Saturday the Egyptian army launched an offensive against Islamist militants near Sheikh Zuweid in North Sinai. The troops deployed dozens of tanks as well as armoured vehicles and attack helicopters, killing at least nine militants and arresting nine suspects, security officials said.
The army said nine militants had been arrested.
Sinai's eastern border with Israel and Gaza is a particularly sensitive one, and Israel made its concerns known when jihadist groups expanded into a security vacuum left by the fall of Egypt's veteran autocrat Hosni Mubarak in 2011.
Many of Mursi's critics accused him of helping the jihadists by releasing militants with links to Sinai shortly after he took office in June 2012. Mursi argued that all those set free had either completed their terms or failed to receive due process because they had been tried by special military courts.
Attacks on Egyptian security forces in Sinai have become a near-daily occurrence, and around 50 have been killed since Mursi was deposed.
ATTACK ON SUEZ CANAL
A week ago, militants fired rocket-propelled grenades at a ship passing through the Suez Canal on the Sinai's western edge, vital to world trade as well as Egypt's depleted state finances. A video was released linking them to the al-Furqan group.
Since the army toppled Mursi on July 3, and especially since security forces killed hundreds of Islamists when they smashed protest camps in Cairo on August 14, there have been online calls from radicals to abandon attempts to achieve Islamist rule by democracy, and instead step up violence.
Fears have grown in Egypt of a return to the Islamist insurgency of the 1980s and 90s.
In its statement, Ansar Bayt al-Maqdis promised "revenge for Muslims against whoever helped in killing or assaulting them, and the first of these are (army chief General Abdel Fattah al-)Sisi and Mohamed Ibrahim".
It added: "We are ready to die for the sake of establishing the religion of God on Earth ... and we refuse to take the path of the atheist democracy."
In addition to mounting military operations in Sinai, Egypt's army and has closed tunnels that it believed were being used to smuggle arms to and from the Gaza Strip, run by the Islamist Hamas group, an offshoot of Mursi's Muslim Brotherhood.
Amid speculation that Egypt and Israel are actively cooperating on security in the peninsula, Ansar Bayt al-Maqdis said last month that four of its members had been killed by an Israeli drone strike in North Sinai.
The Egyptian army denied Israeli involvement and Israel declined to comment.
On Sunday, Israeli Strategic Affairs Minister Yuval Steinitz told a security conference near Tel Aviv:
"Today's Egyptian campaign in Sinai is of the utmost importance, to them of course, but also to us in terms of keeping the quiet in the south and preserving the peace between Israel and Egypt."
(Additional reporting by Ahmed Tolba in Cairo, Yousri Mohamed in Ismailia and Dan Williams in Jerusalem; Writing by Kevin Liffey; Editing by Andrew Roche)