The leader of Lebanon's Hezbollah says his group and its allies will not back caretaker Prime Minister Saad al-Hariri.

Former Haitian President Jean Claude "Baby Doc" Duvalier makes a surprise return to Haiti, 25 years after he was overthrown by a popular revolt.

Chinese President Hu Jintao says the international currency system dominated by the US dollar is a "product of the past", ahead of a visit to Washington.

Maria Sharapova wins on the opening day of the Australian Open in Melbourne, with Caroline Wozniacki and Roger Federer in action later.

The climate secrets of the ocean's deepest spot - the Marianas Trench in the western Pacific Ocean - begin to be unlocked by scientists.

The myth of perfect parents is putting mothers under pressure to lie about their own parenting skills, a survey suggests.

The UK government should put a moratorium on shale gas operations until the environmental implications are fully understood, a report says.

The upheaval in the NHS in England is unnecessary as the same results could have been achieved by small changes, leading GPs say.