Tanker attack gives oil prices a boost. Here's why it's unlikely to last

London (CNN Business)Reports of another attack on oil supply in the Middle East pushed prices higher early on Friday but the gains faded fast as markets focused again on weaker demand growth and a supply glut that shows no signs of evaporating.

The International Energy Agency said in its monthly report that commercial oil stocks held by OECD countries were close to record levels of more than 3 billion barrels, a level last seen in 2016. IEA member states hold an additional 1.6 billion barrels in strategic reserves.

At the same time, the IEA cut its forecast for oil demand growth this year and next due to the slowing global economy, and said a new wave of production was expected to come on stream, outweighing fears about supply security.

Iranian state news agency IRNA reported Friday that an oil tanker belonging to the National Iranian Oil Company had been hit by two missiles, causing oil to spill into the Red Sea.