COPENHAGEN (Reuters) - The disruption to container shipping traffic in the Red Sea is worsening, and is expected to reduce the industry's capacity between the Far East and Europe by some 15%-20% in the second quarter, shipping group Maersk said on Monday.

The company, viewed as a barometer of world trade, last week said that shipping disruptions caused by Houthi militants' attacks on vessels in the Red Sea were expected to last at least until the end of the year.

"The risk zone has expanded, and attacks are reaching further offshore," Maersk said in an advisory to customers on Monday.

"This has forced our vessels to lengthen their journey further, resulting in additional time and costs to get your cargo to its destination for the time being," it added.

The knock-on effects of the situation included bottlenecks and so-called vessel bunching, where several ships arrive at port at the same time, as well as equipment and capacity shortages.

"We are doing what we can to boost reliability, including sailing faster and adding capacity," Maersk said, adding that it had so far leased more than 125,000 additional containers.