According to an Israel Radio report, police said that the guard opened fire during the attack. The attacker was wounded in the firing.
According to the initial reports, the attacker is a 41-year-old Jewish man from the city of Bat Yam who has a criminal record.
"A Mazda car stopped next to the U.S. Embassy and a man got out carrying a red bag and a pitchfork," Reuters quoted David Cohen, an eyewitness, as saying.
"He began to run toward the security guards. They saw him, took their guns out and told him to get down on the ground," Cohen said.
He was armed with a knife and an axe and the attack might have been criminally motivated, the police said.
The attack occurred ahead of Secretary of State Hillary Clinton’s visit to Israel later in the day. Clinton is expected to hold talks with Israeli Prime Minister Benjamin Netanyahu to push for a ceasefire between Israel and Hamas.