Egypt's army vowed Monday to "avenge" the killing of 16 troops by gunmen near the Israeli border, as President Mohammed Morsi ordered security forces to take full control of the Sinai Peninsula.

In Sunday's attack, 35 gunmen in Bedouin clothing opened fire on the troops before crossing into the Jewish state in an armored vehicle, Egyptian officials said. Israel said five gunmen were killed on its side.

Germany said Monday that the defection of Syrian prime minister Riad Hijab pointed to the rapid "erosion" of the regime of President Bashar Assad.

"The reports show how far the erosion process of the Assad regime has progressed," Foreign Minister Guido Westerwelle said in a statement.

Militiamen who sided with the Yemeni army in battling al-Qaida "arrested" four jihadists allegedly involved in a suicide bombing that killed 45 people over the weekend, a local official said on Monday.

"The Popular Resistance Committees, in cooperation with the army, arrested four al-Qaida members suspected of involvement in Saturday's suicide attack," local official Mohsen bin Jamila told Agence France Presse.

An overnight blast in southeastern Turkey interrupted oil flow from Iraq, a Turkish energy ministry official said Monday.

The blast hit the Kirkuk-Ceyhan pipeline in Mardin province close to Turkey's border with Syria and repairs are expected to take up to 10 days, the official added on customary condition of anonymity.

Israeli Prime Minister Benjamin Netanyahu on Monday expressed regret over the deaths of 16 Egyptian guards in an attack on Sunday by gunmen on the border with Israel, his office said in a statement.

It said that he was speaking during a visit with Defense Minister Ehud Barak to the site where five attackers crashed across the frontier in an armored vehicle into the Jewish state, where they were killed by Israeli forces.

The leader of the opposition Syrian National Council said the defection on Monday of Prime Minister Riyad Hijab showed the regime of President Bashar Assad is "disintegrating."

"We welcome the defection of Riyad Hijab and those of all the other civilian and military officials," Abdel Basset Sayda told AFP by telephone.

Mauritania's president on Monday ruled out extraditing Abdullah al-Senussi before the feared ex-spy chief for Moammar Gadhafi faces trial in Mauritania for illegal entry.

"Senussi has problems with Mauritania's judiciary and has to face court for entering Mauritania under a false identity," President Mohamed Ould Abdel Aziz said overnight during a local forum in the town of Atar.

Syrian Prime Minister Riyad Hijab has defected to the opposition in protest at the "genocide" President Bashar Assad is carrying out against his own people, his spokesman said on Monday.

"I announce my defection today (Monday) from the regime of killing and terror, and I join the ranks of the revolt," he said in statement read by his spokesman Mohammed al-Otri on Al-Jazeera news channel from Amman.

Qatar and Saudi Arabia are giving light arms to Syria's rebels but the fighters do not have the advanced weapons needed to confront Bashar al-Assad's regime, a spokeswoman for the opposition SNC said Monday.

"Rebels on the ground are searching desperately for arms wherever they can find them," a spokeswoman for the Syrian National Council, Bassma Kodmani, told France's Europe 1 radio.

Israel has improved the accuracy of its Arrow 2 missile interceptor system, including its ability to intercept medium-range missiles present in the arsenals of Iran and Syria, media reported on Monday.

The new system, known as "Block 4," will be installed in missile batteries in the coming weeks, reports said.