The number of people filing initial claims for state unemployment benefits dropped by 20,000 to a seasonally adjusted 512,000, the U.S. Labour Department said Thursday.

That's the lowest level recorded since January, but they have now remained above 500,000 for 51 consecutive weeks.

The figure was in line with economist expectations.

Continuing claims fell by 68,000 to a seasonally adjusted 5.75 million, the lowest level since March.

It's not clear to what extent the decrease in jobless claims was due to the unemployed finding new jobs, and how much can be attributed to still-jobless Americans simply running out of benefits.

Most states offer 26 weeks of benefits, but earlier this year, Congress approved federally funded extensions of up to 53 weeks in some cases.

As of the week ended Oct. 17, 38 states and the District of Columbia were offering extended unemployment benefits, the Labour Department said in a release.