By Emma Graham-Harrison

Buñol, Spain - Tons of flying tomatoes streaked the streets of Buñol red and left 20 000 visitors wallowing in a pond of pulped fruit as the tiny Spanish town celebrated the world's largest food fight on Wednesday.

Locals boarded up windows and locked their doors as drunk but determined revellers donned goggles to prepare for the arrival of six trucks carrying 130 tons of the edible missiles that give the annual "Tomatina" festival its name.

The red frenzy began in 1944, when bored doctor Paco Garces Sanchez and some friends tried to throw tomatoes into the trumpet of a passing musician. The next year they pelted balloons launched for the town fiesta.

"The year after that we decided not to wait for balloons or anything, we all set out with our tomatoes... but the mayor got very angry and called the Civil Guard," Garces told Reuters.

The hour-long pelting session on Wednesday turned the town square into a mass of slimy bodies, with some paddling in a waist-high pool of frothy tomatoes.

"It's fantastic, the most fun I have ever had. I've been waiting for this day since January," pulp-smeared Irish tourist Clarissa Hills shouted as tomatoes whizzed past her head.

The festival was banned in 1948 after an unlucky government official arrived in the town 40km west of Valencia on Tomatina day and was greeted by a hail of tomatoes. Grieving residents held a symbolic funeral for their festival by burying a giant tomato.

"All Bunol came along, dressed in black. There was a procession with a band at the front playing funeral marches and a band at the back playing paso dobles (festival music)," Garces said.

The mayor eventually relented and agreed to reinstate the festival.

But not all Buñol is happy with a fiesta that costs the town nearly €50 000 and attracts a flood of heavy-drinking outsiders.

Garces said its growing popularity has ruined some of the fun. "Now you can't even throw a tomato, there is no room to aim because people are right on top of each other," he said.

Younger locals also worry about foreigners' techniques.

"People from outside don't know how to throw them; you have to squash them first so they don't hurt when they hit," said Irene Recueroaquila, 18, a student from Buñol.

And some tourists were overwhelmed by the mess.

"This is absolutely disgusting, I wish I had never come. I hate tomatoes," said 23-year-old Australian tiler Joel Gorth.

"I'm never eating a tomato again," said 26 year-old London lawyer Laura Janes, pulling seeds from her hair.