Police are advising drivers to avoid the M25 until mid-afternoon after a lorry fire closed the carriageway on both directions in Hertfordshire.
The section between junctions 21a and 23 near the South Mimms services is expected to be closed until 3pm.
Long tailbacks have built up on surrounding roads.
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A 16-year-old boy accused of killing two people in Colchester has appeared in court today.
A fine and generally dry day with a light breeze and plenty of long sunny spells, though becoming cloudier through the afternoon.
Saturday will be the best day this weekend before rain on Sunday.