KINGS Cross main line station has been evacuated due to a fire at a nearby building site.

About 630 people have been evacuated as firefighters fear the blaze could spark a gas explosion.

"Kings Cross national main line station has been evacuated due to a fire at a building under construction on Goods Way at the junction of York Way in Kings Cross this morning," a London Fire Brigade spokesman said.

"An acetylene cylinder is involved in the fire and a 200 metre exclusion zone has been set up as a precaution as some cylinders can explode when exposed to heat."

One person has been taken to hospital by London Ambulance Service crews suffering burns.

Four fire engines and about 20 firefighters are battling the fire, which began just after 8.36am.

Trains are currently terminating at Peterborough and Finsbury Park, while the Tube service is unaffected.