LOS ANGELES (AFP) - A United States (US) city welcomed on Wednesday a court ruling which could force the closure of a US factory that makes famed Sriracha chili sauces, after neighbours complained of spicy smells.

The California city of Irwindale, outside Los Angeles, asked last month for Huy Fong Food's facility to be closed and that the company be forced to improve odour-filtering measures.

On Tuesday LA Superior Court judge Robert H. O'Brien ruled in favour of the city, ordering the sauce maker to stop any operations that could cause smells and immediately take steps to lessen the odors.

The full impact of the ruling was not immediately clear. It does not stop the company operating completely or say what actions need to be taken, according to the LA Times.

But the city hailed the decision.

"We are pleased by the ruling and expect that it will be final and in force by December 9," Irwindale City Attorney Fred Galante told AFP, without elaborating.

The legal action has threatened next year's supplies of Chili Garlic, Sambal Oelek, and the wildly popular Sriracha "rooster" sauce, according to the Los Angeles Times.

The chilis for next year's sauce supplies are all harvested and ground in a three-month time period that is just completed, but the bottling and mixing is continuous, the Times said.

Representatives for Huy Fong Foods have not responded to requests for comment on the ruling.

Sriracha sauce, of which Huy Fong Foods is the biggest producer in the US, takes its name from the town of Si Racha in Thailand, where the hot sauce was first produced.