What do we really know about what happened?

- What we know at the moment is that synchronized drone attacks were carried out against two Saudi oil plants owned by Saudi Aramco - which play a pivotal role for Saudi Arabia's economy. It was an advanced attack, because these oil plants are heavily fortified with defense rings all around. Following the attack, the Saudi Arabian announced that it has cut its oil production by half, affecting the availability of oil on the world market, says SVT's Middle Eastern correspondent Stina Blomgren.

Who's behind it? Has anyone assumed responsibility?

- Shortly after the attack, the Yemeni Iran-backed Huthirbells took on the responsibility. They have carried out several attacks in Saudi Arabia in the past, and are fighting against Saudi Arabia in the civil war in neighboring Yemen. The US, on the other hand, has designated Iran as responsible. Tensions between Iran and Saudi Arabia have risen recently - but Iran denies any involvement and says it is baseless accusations.

What could be the consequences?

- On the one hand, there is increased tension between Saudi Arabia and its arch-enemy Iran. Saudi Arabia says it is prepared to fight back against those who carried out the attack. Should an attack by Saudi Arabia come against Iranian targets, the situation would escalate very dramatically.

- Another consequence is rising oil prices. Saudi Arabia says it had to cut its oil production by half as a result of the attack. At the same time, the country is the world's largest oil exporter. If such a large part of oil production is stopped for a long time, we will see a clear effect on oil prices.