BELGRADE, Yugoslavia (AP) _ The country's Communist leadership today told newspapers to stop criticizing the army and accused them of trying to destabilize the country.

The call came in a sharply worded statement carried by the major state-run newspapers. It was triggered by a series of articles published in the republic of Slovenia criticizing the army's policies as undemocratic.

The ruling State Presidency said ''this slanderous campaign'' sought ''to tarnish the reputation'' of the army and destabilize the country in general.

Criticism of the army and its leadership, published in the Delo daily and Mladina youth weekly, centered on a February visit by Defense Minister Branko Mamula to Ethiopia and plans to develop a domestic supersonic fighter.

Delo, in an article entitled ''Admiral in the Middle of Hunger,'' said that Mamula traveled to Ethiopia to sell arms instead of offering food and financial aid to the famine-stricken land.

Mladina demanded that Mamula resign and said, ''No one can be blamed for being subordinate in Mamula's army.''

The statement said such attacks are ''contrary to the Yugoslav constitution and laws'' and demanded ''that all state organs ... take measures for their prevention.'' The wording indicated possible legal action against the newspapers and journalists.

The Belgrade Politika daily commented recently that Mladina's writing represents ''an open call for mutiny'' in the military and charged the weekly depicted the army as ''an alleged carrier of the approaching military coup and a protagonist of the pro-Soviet military concept.''

Several high-ranking military leaders, including Mamula, have recently voiced the army's concern about the deteriorating economic and political situation in this Communist non-aligned country.

Yugoslavia is faced with 170 percent inflation - Europe's highest - a sharp drop in living standards and increasing labor unrest.

Mladina also criticized the military for plans to invest at least $2 billion to develop a new supersonic fighter, despite deep economic recession and a $19-billion foreign debt.

Mladina is a mouthpiece of Slovenia's increasingly vocal pacifist groups. The groups have demanded radical cuts in defense spending and other reforms in the armed forces to counter severe economic and social problems.