Clever ways to make ships more efficient, including blowing tiny bubbles under their hulls.

We all like getting Christmas post, but what if you didn't have anyone to send you so much as a card?

A selection of the best news photographs from around the world, taken over the past week.

It's often the case that jihadist attacks are carried out by individuals already identified as a risk.

DR Congo is using e-voting for the first time, but is it a secure system?

Financial markets had seen smooth sailing in recent years. But it looks like that's over.

Yemen's truce deal is fraught with risk, but it brings the country a step to closer to elusive peace.

PM Scott Morrison says Australia will not immediately move its embassy from Tel Aviv.

Politicians must compromise and find a plan that a majority in Parliament can support, minister says.

The challenge from a coalition of 20 US states is now likely to go to the US Supreme Court.

The move has angered the Russian Orthodox Church, which fears its property in Ukraine could be seized.

Craig Levein is "embarrassed" at his side's 5-0 defeat by Livingston and says they made the hosts look like Paris St-Germain.

A tram derails and overturns in the Portuguese capital, but no serious injuries are reported.

Manchester City midfielder Kevin de Bruyne finished last season "exhausted", according to his manager Pep Guardiola.

Mahinda Rajapaksa's resignation could bring to an end weeks of political crisis.

Rows continue over paying poorer countries for damages caused by rising temperatures.

India captain Virat Kohli makes an unbeaten 82 to lead his side's recovery on an absorbing second day of the second Test in Australia.

The drone was being flown at more than 20 times the permissible height, close to a Boeing 737.

Dozens are arrested across France, as fewer protesters than in recent weeks defy the government.

England lose a third consecutive men's Hockey World Cup semi-final as they are thrashed 6-0 by Belgium in India.

The three Balangiga church bells return to the Philippines after 117 years in US possession.