By Maggie Fick
CAIRO (Reuters) - Gunmen killed three policemen and a soldier in Egypt's Sinai region on Monday, security sources said, and Islamist militants released a video of an earlier drive-by shooting of an army colonel, highlighting growing security risks to the government.
Violent disorder has gripped the Sinai Peninsula since the army overthrew elected President Mohamed Mursi, an Islamist, in July, plunging the most populous Arab nation into turmoil.
An ensuing security crackdown on Mursi's Muslim Brotherhood, including the arrest of many of its top leaders, has raised fears that Islamists will hit back with violence.
In the latest bloodshed, gunmen killed two policemen as they ate breakfast outside a police station in the city of El-Arish in North Sinai. A police officer out walking elsewhere in the city was fatally shot in the head and chest. Gunmen also killed a civilian in the nearby town of Sheikh Zuwaid.
The security sources also confirmed that gunmen had killed a colonel, identified as Mohamed al-Komi, on August 14 on a desert highway near the Suez Canal city of Ismailia.
Later on Monday, gunmen targeting an armored personnel carrier stopped at a checkpoint killed a soldier in El-Arish, the state news agency reported.
Almost daily attacks by al Qaeda-inspired militants in the Sinai have killed more than 100 members of the security forces since Mursi's ouster, the army spokesman said on September 15.
Militant violence elsewhere in Egypt has raised concerns that an Islamist insurgency, like one eventually crushed in the 1990s by then-autocratic president Hosni Mubarak's government, could take hold beyond Sinai.
The Sinai-based Ansar Bayt al-Maqdis group claimed responsibility for a failed suicide bombing in Cairo on the interior minister this month.
Instability in Sinai worries Western governments because the peninsula borders Israel and flanks the strategic Suez Canal, the quickest sea route between Asia and Europe.
State neglect has long stoked resentment among the Sinai's Bedouin population. Authorities have done little to promote economic development in the vast, largely lawless desert region, whose coast has a string of resorts favored by Westerners.
The army says the Sinai is hard to police partly because it borders the Gaza Strip, which is run by Hamas, an offshoot of the Muslim Brotherhood. The military says Gaza-based militants take part in attacks over the border and accuses Hamas of doing too little to stop them, allegations the Islamist group denies.
U.S. MILITARY MISSION
Egypt's Western allies are hoping to ease political tensions which have hurt the fragile economy in the country of 85 million. A delegation of senior U.S. military officials arrived in Cairo for a two-day visit, state newspaper Al Ahram reported.
U.S. Assistant Secretary of Defense for International Security Affairs Derek Chollet is expected to meet senior Egyptian officials to discuss U.S. military assistance.
Washington provides the Egyptian military - the biggest in the Arab world - with $1.23 billion in annual aid. That assistance came under scrutiny after the military ousted Mursi.
European Union foreign policy Catherine Ashton is due to arrive late Tuesday night for a two-day visit that will include talks with the army chief, General Abdel Fattah al-Sisi.
Although the EU had tried to play the role of neutral broker between the army and the Brotherhood in previous mediation missions, Ashton's leverage with the army-backed government has proven limited.
Attacks in Sinai have risen sharply since Mursi's overthrow, although militants and smugglers had already been exploiting a security vacuum left by the 2011 fall of Mubarak to an uprising.
The current government says it is fighting a war on terror and does not distinguish between the Brotherhood and Sinai militant groups.
Interior Minister Mohamed Ibrahim said in a speech on Monday that the police are capable of "repelling thuggery and terrorism", the state news agency MENA reported.
Sinai militants have published online footage of some of their attacks - a common practice among al Qaeda-linked groups trying to motivate fighters and intimidate their enemies.
In a video posted on a jihadi website on Monday, a group calling itself "al-Nusra Battalion" shows what appears to be footage of security forces firing on Mursi supporters.
The video then shows what it says was the attack on Colonel Komi on August 14, the day security forces crushed pro-Mursi protest camps in Cairo, killing hundreds of people.
A man with an assault rifle is filmed aiming from a car window and shooting at another vehicle driving on a desert road.
"Targeting the criminal apostates and liquidating them," a caption reads.
A picture of the uniformed officer flashes on the screen next to the car seen in the drive-by shooting, a back window pocked with bullet holes and blood running down the driver's door after what appears to have been a well-planned assault.
"It's likely that they learned his daily routine ...by a combination of relatively good intelligence on their part and perhaps poor operational security on the part of the Egyptians," said David Hartwell, a Middle East analyst at IHS Jane's.
The video says al-Nusra Battalion is a unit of "al-Firqan Brigade", a militant group that took responsibility for an attack this month on a container ship in the Suez Canal.
The army, which has been operating with the police in Sinai, said on August 7 that it had killed 60 militants in the month since Mursi's overthrow.
"There are great security successes on the ground in Sinai now," Interior Ministry spokesman Hany Abdel Latif said when asked about the al-Nusra Battalion video.
"We've arrested dangerous elements and confiscated heavy weapons, and we have a large degree of control."
(Editing by Michael Georgy/Mark Heinrich)