BUENOS AIRES, Oct 28 (Reuters) - The Argentine government and oil companies on Saturday said fuel shipments are starting to arrive that in coming days should ease a shortage, after a spike in demand caused long lines at gas stations.

Ten fuel shipments imported by the government are beginning to arrive, although distribution may take a few days, Energy Secretary Flavia Royon told a local radio station, noting that there would be no abrupt price increases.

Royon attributed the shortage in part to tourism during a long weekend and rumors of possible price increases following the Oct. 22 presidential election. The run-off vote is Nov. 19.

"It generated a psychosis of 'you have to go and fill up the tank'" she said.

Argentine refineries supply 80% of the local market while the rest comes from fuel imports.

Long lines at the pump have added to frustrations for Argentines already under the strain of an economic crisis with inflation close to 140% and a currency that has lost 42% in value this year.

Oil companies YPF, Raizen, Trafigura and Axion Energy in a joint statement on Saturday said the supply will be normalized in the next few days.

Among the factors causing the shortage, the companies cited high demand, the presidential elections, the beginning of crop planting and a higher than usual dependence on imports.

They also flagged "excessive demand caused by the expectation of a shortage."

The diesel supply is of special concern to farmers, who say a shortage could impact the start of planting, key for the country's major soy and corn crops. (Reporting by Lucila Sigal; Additional reporting by Walter Bianchi; Writing by Daina Beth Solomon; Editing by David Gregorio)