Former South African president Nelson Mandela remained in hospital for a tenth straight day Monday after receiving treatment for a lung infection and gallstone surgery, the president's office said.

"If there's any changes we'll announce it. In the absence of that, work on the basis that he is continuing to improve," presidential spokesman Mac Maharaj told Agence France Presse.

Dozens of British lawmakers signed an open letter published Monday opposing government plans to introduce same-sex marriages.

A cross-party group from the elected lower House of Commons and the largely appointed upper House of Lords signed the letter to The Daily Telegraph newspaper warning ministers that they had no mandate to "redefine" the meaning of marriage.

Egypt's opposition is calling for mass protests on Tuesday after Islamists backing President Mohammed Morsi claimed victory in the first round of a referendum it alleges was riddled with polling violations.

The opposition coalition, the National Salvation Front, urged Egyptians to "take to the streets on Tuesday to defend their freedoms, prevent fraud and reject the draft constitution" ahead of the next round of voting on Saturday.

British oil giant BP said on Monday that it had agreed to sell its 50-percent stake in a North Sea gas field to energy firm SSE as part of its divestment plans.

"BP announced today that ... it has agreed to sell its interest in the Sean gas field in the UK North Sea to SSE plc for $288 million (219 million euros) in cash," it said in a statement, adding it will complete the deal in the first half of 2013.

A French auction house is to put on sale Monday a historic Chinese seal despite threats of legal action alleging the piece may have been stolen from Beijing's Forbidden City by Anglo-French forces in 1860.

The green jade seal is expected to fetch up to 200,000 euros ($263,000) and dates from the Qianlong period (1736-95).

Protesters on Monday hurled rocks at Tunisia's President Moncef Marzouki and parliamentary speaker Mustapha Ben Jaafar in Sidi Bouzid, cradle of the revolution that erupted exactly two years ago.

The incident began after a speech by Marzouki in the central Tunisian town, where celebrations are taking place to mark the anniversary of the revolution, and as Ben Jaafar was about to speak.

Swiss insurer Zurich Insurance Group said on Monday that Superstorm Sandy had hit it with claims worth about $700 million (532 million euros).

"It's difficult to say exactly how much the final amount will be. It could be a bit higher or a bit lower (but) usually our estimates are good," Sylvia Gaeumann, a spokeswoman for the insurer told Agence France Presse.

Two explosions rocked police stations in the Libyan city of Benghazi early on Monday and police foiled a third attack, a security official told Agence France Presse, adding that there were no casualties.

Police in the eastern city had placed checkpoints and bolstered security around their stations following two Sunday attacks, blamed on radical Islamists, which claimed the lives of four officers, an AFP correspondent said.

Romanian President Traian Basescu on Monday reappointed his arch-rival Victor Ponta as prime minister following elections, allaying fears of new political turmoil in one of EU's newest members.

Ponta's ruling center-left Social-Liberal Union (USL) won the December 9 parliamentary polls with 60 percent of the vote, well ahead of the center-right alliance supported by Basescu.

Iranian President Mahmoud Ahmadinejad canceled a planned Monday visit to Turkey, his office said a day after his foreign minister warned Ankara over hosting Patriot missiles on its border with Syria.

Ahmadinejad had been officially invited to and was scheduled to attend the annual commemoration ceremony for Mevlana Jalal ad-Din Rumi, the 13th century Persian Muslim theologian.