Roughly 6,000 federal inmates will be released in the coming weeks in an effort to ease prison crowding and lessen harsh penalties for non-violent offenders, US media report.

The release is the biggest of its kind in US history, the Washington Post reported.

The inmates being released early were all convicted of drug-related charges. An additional 8,500 inmates will be eligible for release starting in November.

The US Sentencing Commission unanimously approved the reductions to the jail terms of inmates last year.

Up to 46,000 of the nation’s about 100,000 drug offenders could qualify for early release under the commission recommendations.

These 6,000 prisoners are the first wave of early releases. Most of the those released will see about two years trimmed from their original prison terms.

"Even with the Sentencing Commission’s reductions, drug offenders will have served substantial prison sentences," Deputy Attorney General Sally Yates told the Post.

About one-third of the inmates up for release are foreign citizens. They will be quickly deported, officials said.

President Barack Obama’s administration has been working to tackle what he sees as a lack of fairness in the system.

The planned releases continue a drive that started in 2013 when US Attorney General Eric Holder dropped mandatory minimum sentences for non-violent drug offenders.

Many leading Democrats and Republicans now believe that mandatory prison sentences that led to mass incarceration in the US have not been effective.

The US has almost a quarter of the world’s prison population — one in every 99 Americans is behind bars.

Adapted from BBC website