JERUSALEM, July 16 (Reuters) - Israel has allowed Egypt to boost its forces in the Sinai peninsula after Cairo requested additional troops to fight Islamist militants in the lawless region, Israel's defence minister said on Tuesday.

At least three people were killed and 17 wounded early on Monday in Egypt's North Sinai province when suspected militants used rocket-propelled grenades to attack a bus carrying workers employed at a cement factory, security and medical sources said.

Turkish President Abdullah Gül met with Egypt's Ambassador to Ankara Abdel-Rahman Salaheddin on Monday, state news agency MENA reports.

Supporters of ousted president Mohamed Morsy at Nahda Square in Giza threatened on Monday to escalate protests to demand that the toppled leader be reinstated after the army overthrew him to appease demonstrators demanding early elections.

Ziad Bahaa Eddin, candidate for the post of Minister of International Cooperation, has said that the new cabinet will only focus on six main dossiers due to the body's transitional nature.

Egyptian tycoon Naguib Sawiris, whose family controls the sprawling Orascom corporate empire, says he and his brothers will be "investing in Egypt like never before" after the ousting of a president he accused of bullying opponents to his rule.

Egypt announced a criminal investigation on Saturday against deposed Islamist President Mohamed Mursi, with prosecutors saying they were examining complaints of spying, inciting violence and ruining the economy.

Egyptian businessman and opposition leader Mounir Fakhry Abdel Nour has accepted an offer to become Investment Minister made to him by caretaker government Premier Hazem El Beblawi, sources reported on Sunday.

The Nour Party has declined an offer to participate in Egypt's new interim administration, according to party vice-president Bassam al-Zarqa.

Prominent media figure Doria Sharaf al-Din said on Sunday she was proud and happy to be the first female candidate from the state radio and television to hold the post of Information Minister.

Egypt's new prime minister is putting the finishing touches on a cabinet that he says will be finalised by mid-week.

A Central Security conscript was killed by unknown assailants at one of the checkpoints in Sinai's Rafah on Thursday morning.

Politically motivated arrests in Egypt make it difficult to see how the country will be able to move beyond its current political crisis, a State Department spokeswoman said on Thursday.

Egypt's new leadership is facing increased difficulties in forming an interim government after it issued an arrest warrant for the leader of the Muslim Brotherhood movement backing ousted president Mohamed Morsi.

The National Salvation Front (NSF) has called for Egypt's new cabinet to include credible revolutionary figures.

The International Monetary Fund on Thursday said it was not currently discussing a possible loan with Egypt's interim government, and its decision on whether to engage would be guided by the views of the international community.

Interim President Adly Mansour has vowed to end the imprisonment of journalists, Al-Ahram Arabic news website reported. The maximum penalty in publishing infractions will now be a fine.

The Nour Party will not be fielding candidates to join the new interim government led by Prime Minister Hazem al-Beblawy, according to party leader Younis Makhyoun.

Ensuring economic stability is one of the most important steps for reaching a sustainable social and political settlement in Egypt. Without the prospect of a better life for all, Egyptians will continue to struggle to come together and agree on the best way forward for their country.

Judge Hisham Barakat took his oath of office as the country’s prosecutor-general on Wednesday, reported the state news agency MENA.

Supporters of Egypt's deposed President Mohamed Mursi uphold their sit-in outside the Rabaa Al-Adawiya Mosque for the 13th day in a row, demanding the return of "legal and constitutional legitimacy" and the abolishing of decisions that followed June 30, reported the State news agency.