BONN, FEB. 24 -- The Soviet Union will begin withdrawing nuclear missiles from East Germany on Thursday that are to be scrapped under the Intermediate Nuclear Forces Treaty signed in December, the East German Foreign Ministry said today.

Military bands were scheduled to perform at ceremonies in two East German towns to bid farewell to the Soviet missiles, the soldiers who operated them and the soldiers' families, according to a program distributed to correspondents in East Berlin.

The SS12 missiles are to be transported to destruction sites deep in the Soviet Union, where they no longer will be within range of the North Atlantic Treaty Organization targets, according to the Soviets. They are to be dismantled after the INF pact is ratified.

Czechoslovakia's Communist Party newspaper Rude Pravo said the Soviet Union also would begin withdrawing SS12s from that country "in the next few days."

The SS12 withdrawal is being carried out before the treaty takes effect to demonstrate the Warsaw Pact's "constructive peace policy," according to an East German Foreign Ministry statement.

The action also was designed to encourage a "rapid" U.S. ratification of the treaty, the statement said. The U.S. Senate currently is debating whether to consent to ratification.

A NATO diplomat said that the Soviets, by staging the early withdrawal, were "trying to gain a few extra brownie points, with their publics and our publics." He added, "We know that there has been some unhappiness in East Germany about the stationing of these missiles."

The SS12s, which have a range of 560 miles, were moved forward from the Soviet Union to positions in East Germany and Czechoslovakia in 1983 in response to NATO's decision to deploy U.S. Pershing II and Tomahawk cruise missiles in five Western European countries. Those missiles also are to be scrapped under the INF Treaty.

The United States has welcomed the early withdrawal of the missiles as evidence that the Soviets are serious about the INF agreement. It had been announced previously that the SS12s would be pulled back early, but a date had not been fixed.

The missiles are to be removed on special trains from the East German towns of Bischofswerda in the south and Waren in the north. According to the treaty's memorandum of understanding, the two towns have 30 of the 54 SS12s deployed in East Germany.

Also deployed in East Germany are SS23 missiles, which are to be dismantled under the INF pact.