PRETORIA, South Africa (AP) _ Leaders of the Dutch Reformed Church, the church of most government officials, have questioned the ethical grounds for keeping South African troops in Angola.

''These are the questions in the hearts of our people,'' said the church's moderator, Johan Heyns.

''While the government may have its reasons for maintaining a military presence in Angola, parents of national servicemen are entitled to ask whether this is necessary.''

He was commenting Thursday on an editorial in the church's newsletter this week in which editor Fritz Gaum asked if the government would not be acting ethically if it withdrew its troops from Angola.

Gaum said South Africa could become more deeply involved in a struggle on foreign soil, with a corresponding increase in loss of life. Defense Minister Magnus Malan responded by saying the editorial appeared to ignore South Africa's national security interests.

The military acknowledged for the first time in November that its forces were maintaining a long-term presence in Angola and were fighting Cuban soldiers and forces of the Marxist government. South Africa supports the National Union for the Total Independence of Angola guerrillas.

The white branch of the Dutch Reformed Church seldom criticizes government policy. Last year, it reversed decades of church policy, declaring the policy of apartheid a sin and not supported by the Bible. But the church has not criticized specific apartheid laws.

By law and custom, apartheid establishes a racially segregated society in which the 26 million blacks have no vote in national affairs. The 5 million whites control the economy and maintain separate districts, schools and health services.