The 10 most important things in the world right now

Reuters

An aerial view shows that people burn joss paper money as they pray at a public cemetery during Qingming Festival, or Tomb Sweeping Festival, in Fuzhou, Jiangxi Province, China, April 4, 2016.

Good morning! Here's what you need to know on Tuesday.

1. Thousands took to the streets of Reykjavik to call for Icelandic Prime Minister Sigmundur Gunnlaugsson to step down after leaked documents linked him to an offshore company. The connection was revealed in the Panama Papers, a leak of 11.5 million documents from a Panamanian law firm.

2. Nest, a smart-home company owned by Google's holding company Alphabet, is dropping support for a line of products - and will make customers' existing devices completely useless. The move that has infuriated some customers.

3. South African President Jacob Zuma faces an impeachment attempt in parliament on Tuesday after the country's top court ruled that he had violated the constitution over spending on his private residence.

4. Asian shares slipped in early trade on Tuesday, pressured by losses on Wall Street against a backdrop of slumping crude oil prices and mixed messages on the outlook for US monetary policy.

5. The entire Turkish citizenship database has allegedly been hacked and uploaded to the internet. A website purportedly shows the personal details of 49,611,709 Turkish citizens.

6. ISIS militants attacked Syrian army troops with mustard gas in an offensive against a Syrian military airport in the eastern province of Deir al-Zor that borders Iraq, state media said on late Monday.

7. Spanish tax authorities said they are investigating allegations of tax irregularities involving Barcelona and Argentina footballer Lionel Messi following the release of the Panama Papers. Messi and his family deny any wrongdoing.

8. Activity levels across the global manufacturing sector expanded at the slowest pace in nearly three years in the first quarter of 2016. The latest JP Morgan-Markit global manufacturing purchasing managers index (PMI) rose 0.5 points to 50.5 last month.

9. Donald Trump's string of luxury hotel properties, The Trump Hotel Collection, appears to be dealing with the second breach of its credit card systems in a year, KrebsonSecurity reported on Monday.

10. Flash floods triggered by heavy rain in Pakistan have killed at least 55 people. Rescuers were trying on Monday to help thousands of survivors including some cut off by a landslide in a mountain valley.

And finally ... These are the 16 busiest airports in the world.