LONDON (AFP) - US Secretary of State John Kerry on Tuesday condemned an attack on a Jerusalem synagogue that killed four Israelis as an "act of pure terror and senseless brutality".

Speaking in London ahead of talks with British Foreign Secretary Philip Hammond, Kerry called on the Palestinian leadership to denounce the attack, which was carried out by two Palestinians armed with a gun and axes in the Har Nof neighbourhood.

"This morning in Jerusalem Palestinians attacked Jews who were praying in a synagogue," Kerry told reporters.

"People who have come to worship god in a sanctuary of a synagogue were... murdered in a holy place in an act of pure terror and senseless brutality and murder.

"I call on the Palestinian leadership at every single level to condemn this in the most powerful terms," he added. "This violence has no place anywhere particularly after the discussion that we had just the other day in Amman."