REUTERS/Marcos Brindicci
Demonstrators shout slogans as they wave Argentine flags during a protest over the death of prosecutor Alberto Nisman, outside the Casa Rosada Presidential Palace in Buenos Aires January 19, 2015.
1. The Islamic State group threatened to kill two Japanese hostages unless a ransom of $200 million (£132 million) was paid, in a new video posted online.
2. The Argentine prosecutor who accused President Cristina Fernandez of covering up Iran's involvement in the 1994 bombing of a Jewish community centre was found dead in his apartment Sunday night, a day before he was set to testify about his claims.
3. Canadian special forces confronted Islamic State group fighters in Iraq in the first confirmed ground battle between the terrorist group and coalition troops.
4. The International Monetary Fund cut its global growth forecast by 0.30 percentage points in 2015 and 2016.
5. The governor of Montana declared a state of emergency after a burst pipeline spilled as much as 50,000 gallons of oil into the Yellowstone River.
6. Four Hong Kong student leaders who participated in last year's pro-democracy protests were freed from police custody without charge, but told they could still be charged following an investigation.
7. A worker at the defunct Fukushima plant in Japan died after falling into an empty water tank.
8. Norway has redefined where the edge of the Arctic lies, opening up new oil and gas licensing opportunities for the county.
9. British tabloid "The Sun" will reportedly end a decades-long tradition of featuring topless women on its page three.
10. Facebook claims in a new study that it adds more than $200 billion (£133 billion) to the global economy.
And finally...
Tigers Woods had his tooth knocked out by a photographer at the World Cup event in Italy.