Overcast skies and a cool wind kept the expected Passover visitors to the north at bay yesterday morning, but by the end of the day some 500,000 Israelis had ventured to national parks and forests across the country.

"The volcano has erupted," said Uzi Barzilai, the Nature and Parks Authority official responsible for visitors, as traffic drew to a virtual standstill at major intersections in the north, including Hamovil and Tzemach junctions, and visitors started pouring in.

The most popular sites run by the authority were the Banias and Caesarea nature reserves, each of which attracted some 4,000 visitors yesterday, Barzilai said.

Some 250,000 Israelis visited reserves run by the parks authority, it said.

The Jewish National Fund reported the same number of visitors - especially bicyclists, hikers and barbecuing families - at its forests and other sites.

A 40-year-old woman and 73-year-old man who were both injured were evacuated yesterday from two streams in the north by volunteers from the Golan Rescue Unit, a non-profit association that helps hikers in the country's north.

The most popular sites in the north yesterday included the Hula Valley, Goren and Adamit parks and Ofer Forest. In the center of the country, the Ben Shemen Forest and Canada Park saw many visitors, as did Sataf and Aminadav Forest in the Jerusalem area, and Golda Park in the south.

Earlier in the day, however, the mood among tour site operators was grim.

"This year we will eat bitter herbs," said the manager of a tourist site near Lake Kinneret as visitors trickled in.

At Rob Roy, a canoeing site on the banks of the southern Jordan River, employee Guy Alon said the short wait was a bad sign.

"If there isn't a line of people, it's a sign that it's going to be a weak Passover," he said.