WASHINGTON (REUTERS/AFP) - US President Barack Obama on Tuesday condemned the attack by two Palestinians on a synagogue in Jerusalem that killed four people, including three Americans, and called on Israeli and Palestinian leaders to lower tensions and seek peace.

"I strongly condemn today's terrorist attack on worshippers at a synagogue in Jerusalem," Mr Obama said in a statement. "There is and can be no justification for such attacks against innocent civilians."

"At this sensitive moment in Jerusalem, it is all the more important for Israeli and Palestinian leaders and ordinary citizens to work cooperatively together to lower tensions, reject violence, and seek a path forward towards peace," he said.

Speaking to reporters at the White House, Mr Obama said US Secretary of State John Kerry had spoken to Israeli Prime Minister Benjamin Netanyahu about the attacks

"Tragically, this is not the first loss of lives that we have seen in recent months. Too many Israelis have died, too many Palestinians have died," Mr Obama told reporters.

He identified the three Israeli-Americans who died in Tuesday's attack by two Palestinians armed with a gun and meat cleavers as Mr Aryeh Kupinsky, Mr Cary William Levine and Mr Mosheh Twersky. The fourth Israeli victim has been identified as a British national. Eight more people were wounded.

"The thoughts and prayers of the American people are with the victims and families of all those who were killed and injured in this horrific attack and in other recent violence."

The attack began shortly before 7:00 am Israel time (1 pm Singapore time) when assailants burst into a Jewish seminary in Har Nof. Police exchanged gunfire with the attackers, killing them. Two police were wounded, one critically.