Russian river continues to supply local administrative districts (7)

I believe the answer is:

oblasts

I'm a little stuck... Click here to teach me more about this clue!

'supply local administrative districts' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'russian river continues' is the wordplay.
'russian river' becomes 'Ob' (river in Russia).
'continues' becomes 'lasts' (I've seen this in another clue).
'ob'+'lasts'='OBLASTS'

'to' is the link.

Can you help me to learn more?

(Another definition for oblasts that I've seen is " Soviet provinces".)

I've seen this clue in The Independent.

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