Britain's economy faces "turbulence" as it negotiates its EU exit and consumer and business confidence could go up and down like a "rollercoaster", finance minister Philip Hammond warned on Monday.

"We must expect some turbulence as we go through this negotiating process," the chancellor of the Exchequer told the BBC ahead of a keynote speech at the ruling Conservative party's annual conference.

Iran offered up to 13 years of tax holidays to hoteliers at an international tourism summit on Sunday as it seeks to boost visitor numbers and revamp its dilapidated hotels.

Thirteen top officials from Banca Monte dei Paschi di Siena (BMPS), Deutsche Bank and Nomura are to go on trial in Milan for their alleged role in a long-running derivatives scandal, Italian newspapers reported Sunday.

Saudi billionaire Prince Alwaleed bin Talal's company has sold the luxury Four Seasons hotel in Toronto for $170 million, it said on Sunday.

Afghanistan's president will meet world powers at a major conference in Brussels next week in a bid to secure financial aid from the international community up to 2020 to rebuild the war-ravaged nation.

Huthi rebels in Yemen are posing a threat to shipping in the strategic Bab al-Mandab strait, the Saudi-led coalition supporting the government said Sunday after an attack on an Emirati vessel.

The coalition said Shiite Huthi militiamen had attacked the vessel "on its usual route to and from (the southern port city of) Aden to transfer relief and medical aid and evacuate wounded civilians."

French carmaker Renault said Friday it would start a joint venture in Iran, tapping into the country's fast-growing car market as it opens up to foreign investment after the end of Western sanctions.

Russia said Friday it was waiting to see the details of OPEC's surprise agreement to cut oil output before deciding on any freeze to its own production. 

"During October and November the OPEC countries will work out the specific parameters of their proposal," Russian news agency Interfax quoted energy minister Alexander Novak as saying.

Shares in Germany's biggest lender Deutsche Bank plummeted on the Frankfurt stock market on Friday, dragging other European banks and global markets down with it, after reports some customers were pulling money out.

The investors were reacting to a $14-billion fine demand from the US Department of Justice (DoJ) and conflicting reports in German media over whether Berlin would come to the troubled bank's aid if necessary, which have sapped the bank's market valuation since Monday.

The Danish tax authority said on Thursday it had paid an anonymous source almost six million kroner (0.81 million euros, $0.9 million) for leaked data from the Panama Papers on hundreds of Danes.