MANAGUA (AFP) -- Nicaragua's National Assembly approved the destruction Thursday of 651 surface-to-air missiles that Washington wants disactivated so they do not fall into terrorist hands.

After a stormy session in which insults were exchanged, legislators voted to destroy the batch of shoulder-fired SAM-7 missiles acquired from the former Soviet Union during the 1980s.

Representatives of the main opposition, the leftist Sandinista National Liberation Front (FSLN), walked out in an attempt to prevent a quorum.

After the vote Thursday the Sandinistas said the 46 deputies who voted for the missiles' destruction, exactly half the assembly, were not enough for a valid vote.

But a member of the right-wing Liberal Alliance deputy said there were 47 deputies present, establishing a quorum, and so the vote was fair.

U.S. officials have sought to convince Nicaragua to eliminate its estimated 1,000 remaining SAM-7s, which Washington fears could be used by terrorists against international aircraft.

In 2005 Nicaragua destroyed 1,000 of the missile. It is still holding on to 400 of the missiles for its own national defense force.