Israel's Olympic Committee voted yesterday to boycott the summer Olympic Games in Moscow because of the Soviet intervention in Afghanistan.

Urged by Prime Minister Menachem Begin and the sports committee of the parliament, the committee voted 17 to 8 to support the U.S. sanctions against the Olympic Games. Seven of the dissenting votes were by members of the sports group of Israel's labor federation.

Yitzhak Ofek, chairman of the Olympic Committee, who voted for participation, said: "We have often been victims of discrimination in international sport and the decision to boycott could cause us problems in the future."

With the British committee's decision "to force a breach in the boycott wall," the official Soviet sports daily declared yesterday, "the campaign launched by transatlantic reactionary circles has suffered a failure."

Sovietsky Sport, organ of the government sports committee, said, "The world's sporting public defended the Olympic ideals . . . Reaction has found itself in isolation."

Lamenting the decision by the U.S., West German and the Canadian committees not to attend, the newspaper said "their absence does not lessen the sporting significance of the games. The Americans long ago lost their leadership in world sports."

At another point the paper said the American effort found support only among "frankly dictatorial and anti-Soviet regimes like Chile, Haiti, China and Egypt."

In other developments, the Japanese committee postponed a decision on whether to participate but agreed to send only potential medal winners if the vote is affirmative. The government has said it will provide no funds for a team to go to Moscow.

Similarly, the Belgian government announced that it will provide no aid to the athletes intending to participate in the games.

The governments of Turkey and Spain declared that the decisions of the committees in those countries, expected today, should be not to participate. The deadline is Saturday.

Luxembourg's Olympic Committee voted 8 to 4 last night to accept its invitation.