PANAMA, April 30--National Guardsmen were ordered to move up to the town of Nombre de Dios today for the first full-scale attack on a band of Cuban-based invaders holed up inside. But they were called back to let a team of neutral observers get in first.

Nombre de Dios, an isolated town on the Caribbean coast only 20 miles from the Panama Canal, was siezed by the rebel mercenaries after they landed from Cuba on Sunday and marched 35 miles up the coast. The band now numbers 89 men and is reported armed with automatic weapons.

President De la Guardia's government is worried that even a small band of invaders might touch off a full-scale revolt. The government also has been increasingly jumpy over reports that a new band, numebring perhaps as many as 300 men, is en route by ship from Cuba.

Ministers Agree on Geneva Plan

PARIS, April 30--Four Western foreign ministers, winding up their pre-Geneva meeting in unexpectedly quick time, proclaimed full agreement today on a plan to break down cold war tensions in Europe.

The ministers announced they had agreed on all parts of a sweeping package plan, including a reiteration of Western rights in Berlin, for presentation to the Soviet Union at the East-West foreign ministers conference in Geneva.

Details of the package plan were shrouded in secrecy that a U.S. spokesman said would be maintained until the opening of the Geneva conference May 11.

House Sustains Veto

WASHINGTON, April 30--By four votes, House Democrats failed today in an all-out bid to break President Eisenhower's six-year record of never having a veto overridden by Congress.

Eisenhower voiced gratification for the vote by which the House sustained his veto of a bill that would have taken from Secretary of Agriculture Ezra Taft Benson the power to pass on rural electrification and telephone loans.

Scientist Scores Strauss

WASHINGTON, April 30--An atomic-scientist accused Lewis L. Strauss today of narrow-minded, vindictive and sometimes unethical tactics, menacing the nation's survival.

Dr. David Rittenhouse Inglis was accused in turn by Sen. Hugh Scott R-Pa. of being vengeful and bigoted in testimony before the Senate Commerce Committee.