It is four years since a group of countries led by Saudi Arabia started to bomb the country of Yemen, in order to remove power from a group of people called the Houthi rebels (anti-government fighters) and reinstate the government, which has fled the country into exile.
There has been conflict in Yemen for a long time and a civil war since the end of 2014.
The government remains in exile and the Houthi rebels still control large areas.
The conflict has had a devastating impact on the lives of people living there, including young children.
In October 2018, the United Nations (UN) - a global organisation that brings countries together to talk about, and try to agree on, world issues - said that 14 million people in Yemen were on the brink of famine.
Many of those were said to be children and, at the time, it was thought that over 85,000 children under five may have died because of starvation. That figure is now likely to be much higher.
The UN also said that, since March 2015, over 7,000 civilians have been killed and over 11,000 injured in the fighting, with many of those due to the Saudi bombs. Some say the figures are actually higher than this.
Read on to find out more about the situation in the country.
The country as we know it today was actually formed quite recently, when south Yemen and north Yemen - which believe the country should be run in different ways - joined together in 1990, after many years of fighting.
However, since then, the fighting has not stopped and there is now a civil war taking place, which has made life for those living in the country extremely tough.
Currently, Yemen is suffering from what has been called the world's worst humanitarian crisis in the last 100 years, with many people not having the essentials that they need to survive, like food, water and shelter.
Despite joining together in 1990, the north and south of the country still disagreed with each other.
Fighting between the government and anti-government fighters (the Houthi rebels) continued.
The situation reached a peak in 2011 when protests led to the president at the time, Ali Abdallah Saleh, resigning and his deputy, Abdrabbuh Mansour Hadi, taking over.
However, the fighting still didn't stop, as Mr Hadi struggled to keep everyone in the country happy.
The rebels took advantage of the new president's weakness and began to take control of areas. Many people supported them because they weren't happy with their country's leader.
At the end of 2014, the country descended into civil war, when the rebels - backed by Iran - took over the capital city of Yemen called Sanaa.
President Hadi fled to Saudi Arabia next door, which leads a group of 10 countries called a coalition in support of the Yemeni government.
In March 2015 - exactly four years ago - Saudi Arabia and its supporting countries started to bomb Yemen. They said they wanted to push out the Houthis and reinstate the legitimate government. The US, UK and France supported these strikes.
When President Hadi fled, he set up a temporary capital in a different city in Yemen called Aden, and has still not been able to return to Sanaa.
This civil war is still going on today and the country is locked in a difficult situation.
At the start of the war, Saudi officials said they believed the war would last only for a few weeks.
But four years later, the Houthis remain in Sanaa and the conflict continues.
The Houthi rebels don't accept that Hadi's government makes their rules. They believe in a new ruling group with a leader called Mohammed Ali al-Houthi.
However, much of the rest of the world - including the UK and the US - do not accept this. They both support the government in Saudi Arabia.
So, it is a civil war that has become more of a regional one, as other countries have got involved.
The UK and others have called for a ceasefires in Yemen, calling on Saudi Arabia and its allies to end the war against the Houthi.
But they continue to sell weapons to Saudi Arabia, which leads the pro-government forces, so this helps the fighting to continue. Many people have been critical of this.
The UN wants the two sides to talk to each other to try to sort out their problems.
Both groups agreed to a deal to stop fighting at talks in Sweden on 13 December 2018 and some hoped it would be the starting point to bring nearly four years of civil war to a close.
But the ceasefire in Yemen's war was broken minutes after coming into effect on 18 December, pro-government officials said.
There were reports of clashes between the Houthi rebels and pro-government forces in the port city of Hudaydah, which is an important place for food, fuel and medicine to get into the country.
In December, government and Houthi fighters agreed to a ceasefire in Hudaydah city and promised to move their soldiers by mid-January. But this has not happened yet, so people are worried the fighting there could get worse again.
Another thing that has made the situation in Yemen more difficult is that, because of all the fighting and unrest, it became a place for extreme groups like Al-Qaeda and the group that calls itself Islamic State to base themselves and grow stronger. The groups have carried out attacks in the south of the country.
It has also always been one of the poorest Arab countries, which has made it difficult to deal with the situation.
The fighting has had a devastating impact on ordinary people who live in Yemen.
Restricted deliveries of food and fuel, and roads and buildings being destroyed, has led to millions of people not having the basic essentials that they need to live.
The price of food has got incredibly expensive and many people cannot afford to eat.
People also don't have access to the healthcare they need. In 2017, there was an outbreak of cholera in Yemen, due to poor sanitation and people not being able to get the treatment they needed, which killed many people.
Over 3 million people have also been forced to flee from their homes. But with airports closed and borders blocked, many are unable to leave the country, despite the problems.
In February 2019, UN emergency relief boss Mark Lowcock said: "Figures suggest that about 80% of the population - 24 million people - need humanitarian assistance and protection."
Charities are working hard to try to help those affected by the crisis.
A UK organisation called the Disasters Emergency Committee (DEC), which represents 13 aid charities, launched a big appeal asking for people to donate money to help make sure that people in Yemen have what they need to live.
The British Red Cross - a charity represented by the DEC - said: "The ongoing conflict in Yemen has devastated millions of people's lives."
Another charity, Save the Children say they are "horrified" by the number of the children who have died as a result of extreme hunger, adding: "For every child killed by bombs and bullets, dozens are starving to death and it's entirely preventable."
For now, the conflict continues and life for millions of people in Yemen continues to be a fight for survival.