Small cylindrical clay objects discovered in recent decades in the north of Israel and Jordan Valley are believed to be the earliest matches, dating back some 8,400 years, Israeli archaeologists say.

Until recently the rods - some 10 centimeters long and 1 centimeter thick - were assumed to be phallus-like ritual artifacts. But a study led by archaeologist Professor Naama Goren-Inbar of the Hebrew University of Jerusalem suggests they are the earliest fire-lighting devices discovered so far.

"What do we know of fire? Ashes, embers, layers of earth in the center," says Goren-Inbar, who has been studying the early use of fire for many years. In excavations she conducted at a sites in the Golan she found the earliest evidence of fire use in Euroasia some 750,000 years ago.

Her present study, published in the open access peer-reviewed scientific journal Plos One in May, was sparked by an exhibition she visited at the Israel Museum a few years ago, where she saw clay rods from the eighth millennium BP (more than 8,000 years ago ) that had been found in Sha'ar Hagolan. The rods were displayed beside women's figurines and described as phallic representations.

"I looked at them and saw they could be interpreted differently," she says.

Her expertise in the early uses of fire led Goren-Inbar to the conclusion that the artifacts were part of a complex fire ignition mechanism, or match-like objects that produced fire by friction.

Drills used to make fire are known from Aboriginal cultures in Australia, American natives and even from ancient Egypt, Goren-Inbar says, but until her study there was no earlier evidence of this tool.

A fire drill was found in the tomb of Tutankhamun and the Egyptian hieroglyph illustrating fire is in fact a drawing of a fire drill, she says. The existence of a fire drill from more than 8,000 years ago shows the technology has hardly advanced over thousands of years, she says.

Examining the rods with a microscope, Goren-Inbar and her colleagues found the rods' edges bore groove marks, indicating a high-speed rotating movement that corroborates the new interpretation.

"Every elongated narrow object is interpreted as a phallic symbol," says archaeologist Yosef Garfinkel of the Hebrew University, who is responsible for digging up the clay rods at Sha'ar Hagai exhibited in the Israel Museum.

"Archaeologists joke that everything they don't understand they attribute to ritual. The earlier interpretation is an excellent example of this," he says.