JERUSALEM, March 26 (Reuters) - The French gunman who went on a killing spree in a Jewish school in France last week traveled from Jordan to the Israel-occupied West Bank in 2010, an Israeli security official said.

The official did not say why Mohamed Merah had made the trip or whether he had also visited Israel, which is next to the West Bank.

He crossed the Allenby bridge and passed a security screening. He stayed for three days before leaving through Allenby again, the official told Reuters on Monday.

The Allenby bridge links Jordan and the West Bank, and most visitors holding foreign passports can easily travel on to Israel, a short drive away.

Israeli media reports said Merah, a French citizen of Algerian origin, told Israeli border authorities at the bridge that he planned to go sightseeing.

Merah, 23, was killed by a police sniper on Thursday as he jumped from the balcony of his lodgings, firing a pistol, after a standoff of more than 30 hours and a gunbattle inside his apartment in Toulouse.

Merah killed three Jewish children and a rabbi at a Jewish school in the city on Monday. The al Qaeda-inspired gunmen also shot dead three French soldiers in the area before the attack on the school.

Israeli media reports over the years have said that al Qaeda operatives have been sent on intelligence-gathering missions in Israel.

Richard Reid, a Briton who tried to detonate a shoe bomb on a U.S. airliner in December 2001, flew to Israel five months earlier on its security-conscious El Al airline in what might have been a dummy run for the future bombing attempt.

Israel captured the West Bank in a 1967 war. Palestinians want the territory as part of a future state.

(Reporting by Dan Williams and Jeffrey Heller, Writing by Jeffrey Heller)