GUATEMALA CITY (AP) _ Guatemala's defense minister has abruptly resigned and a regional army commander has been ousted, days after soldiers killed 11 former refugees of the civil war.

Monday's shakeup dealt a blow to the Guatemalan army, under increasing pressure to end its long history of human rights abuse even as the country prepares for a Nov. 12 presidential election.

A terse presidential announcement on Monday said Defense Minister Gen. Mario Rene Enriquez Morales was replaced by Gen. Marco Antonio Gonzalez Taracena, a member of the government team negotiating to end the war.

President Ramiro de Leon called the resignation the ``correct response by the state, the government, the President and armed institution.'' But his statement made no explicit mention of Thursday's massacre.

Soldiers threw grenades and fired at the refugee settlement community of Aurora 8 de Octubre in Chisec, 80 miles north of the capital. The dead included two children. Fifteen refugees and three soldiers were wounded.

The refugees were meeting to plan a celebration marking the first anniversary of their return from exile in Mexico.

Col. Sammy Noe Vasquez Benavente, commander of the 21st Military Zone in the northern Alta Verapaz province where the attack occurred, was also ousted Monday.

Twenty-four soldiers facing charges for the killings have been detained.

Alta Verapaz was the site of massacres in the early 1980s when the army tried to wipe out civilian support in Indian villages, suspected of collaborating with rebels of the Guatemalan National Revolutionary Unity.

At least 140,000 people have been killed in the 34-year civil war, the longest running in Latin America. Tens of thousands of Indian refugees have fled the violence into neighboring Mexico.

On Monday, 1992 Nobel peace prize winner Rigoberta Menchu warned that failure to fully prosecute those involved in Thursday's massacre could complicate ongoing peace talks, disrupt future refugee returns from Mexico and possibly tarnish the election runup.

``Unless the government prosecutes those involved, the people will lose faith in the democratic and electoral process,'' Menchu said in a telephone interview.

Tensions have traditionally run high between the returnees and the army, which suspects them of ties to the rebels.

Menchu called on the Guatemalan government to challenge a tradition of military impunity and apply the maximum 30-year prison sentence against 26 soldiers accused of taking part in Thursday's attack.

Enriquez, while defense minister, had said refugees provoked the killing spree by disarming and then firing at several soldiers. Human rights groups blame the army, saying the soldiers attacked the villagers.

The townspeople, mostly peasants, are among the 40,000 who fled guerrilla fighting a decade ago in northern Guatemala.

Ronalth Ochaeta, director of the Human Rights legal office of the Roman Catholic archbishop in Guatemala City, warned that if legal action is not soon taken against those suspected in the massacre, a wary public's faith in the country's democratic system would be sorely tested.

More than 3.7 million people are registered to vote in the presidential and municipal elections in Guatemala next month, an important test of that system.