After keeping to cautious statements for weeks about the invasion of Lebanon, top West German government and party officials spoke out sharply today against what they called indiscriminate and irresponsible killing by Israel in the bombardment of Beirut.

West German Chancellor Helmut Schmidt, in an interview with a German newspaper published today, said Israel's actions had bothered him deeply. "Here people are being killed indiscriminately," he declared, "women and men who have nothing to do with the war, who bear no responsibility for this war."

Schmidt said he was disturbed that efforts and warnings by the United States and the European Community had failed to show any effect. He said he understood Israel's motives and interests, but could also understand the motives and interests of the Palestinians, the Lebanese and other Arabs.

"These motives are in conflict," he said, "and the same applies to them as to us in Europe -- that settling conflicting motives and interests with bombs and missiles cannot be reconciled with human dignity."

In tone and substance, Schmidt's remarks went considerably beyond the reserved public posture his government had observed toward the crisis up to now.

Official statements had been limited to a simple deploring of the fighting in Lebanon and to appeals to honor a cease-fire. There were also repeated calls for the withdrawal of all foreign troops and for the restoration of Lebanese sovereignty.

Schmidt's strong words follow several appeals in the past two weeks by editorial writers in leading papers here questioning whether West Germans, because of a sense of guilt about the Jews and, correspondingly, a sensitive attitude toward Israel, need remain silent or uncritical about the invasion of Lebanon.

While West Germany has remained relatively free of openly anti-Semitic or anti-Israel demonstrations in response to the siege of Beirut, senior government aides have voiced concern privately that the tensions and violence that have broken out in France could spread here. They have thus been reluctant to encourage public comments that might be regarded as fanning anti-Jewish sentiment.

The main reason, though, for Bonn's reserve toward Israel -- according to a senior chancellory aide the day before Schmidt gave his interview--was the judgment that strong statements would do little to sway Israel and risked a sharp response from Israeli Prime Minister Menachem Begin, who last year made several attacks on Schmidt.

Condemnation of Israel also came yesterday from spokesmen for Bonn's two governing parties.

Social Democratic Party manager Peter Glotz told a newspaper interviewer that while the Germans had made themselves guilty about the Jews, they would be guilty again "if they accepted in silence Begin's irresponsible path, which costs countless civilian lives."

Juergen Moellemann, the foreign policy spokesman for the Free Democratic Party, was quoted as saying Begin had transformed himself in record time "from Nobel Peace Prize winner to war criminal."

Moellemann, who has long been an advocate of the Palestinian cause, said there was no basic difference between Israeli behavior in Lebanon and Soviet behavior in Afghanistan.

His attack on Begin drew an angry reaction from the chairman of the Central Council of Jews in Germany, Werner Nachmann. In an interview with a German newspaper, Nachmann said the FDP spokesman "had far overstepped the boundary of objective criticism."

The outburst of critical comment threatened to strain again relations with Israel, which had been gradually improving since last year's row over an aborted German tank sale to Saudi Arabia.

Israeli diplomats here, assessing relations with Bonn earlier yesterday, had privately sounded confident that West Germany would avoid strong statements against Israel, because Bonn had long called for the withdrawal of the Palestine Liberation Organization and other foreign groups from Lebanon and because the increasingly popular conservative opposition party here continued to support Israel and America's policy in the Middle East.

One diplomat observed, too, that there was more "common sense" in the relationship between West Germany and Israel than in the spring of 1981 when a remark by Schmidt that West Germany had a moral obligation to the Palestinians prompted Begin to accuse the West German leader of arrogance, impudence, greed and having an active Nazi past.

The Israeli officials said their chief concern recently had been not with the attitude of the Bonn government but with parts of the West German news media, particularly some of the leading weeklies and television news shows, which they said reflected an anti-Israel bias.

The diplomats attributed this to the idiosyncrasies of the publishers of Spiegel and Stern magazines and to the particular biases of individual television correspondents rather than to any more widespread revival of anti-Semitism.

But there are definite signs that Israel's behavior in Lebanon is at least causing West Germans to wrestle deeply against their traditional reluctance to criticize Israel openly.

Last week Theo Sommer, in a lead article entitled "Criticizing Israel--Not Allowed for Us?" in the respected weekly Die Zeit, which he co-edits, declared that the Nazi past should no longer make Germans feel incompetent or without the authority to judge the Jewish state.

"That attitude is wrong," Sommer wrote. Urging the Germans to be faithful to principles and "call injustice injustice," he said: "The thought of Hitler's 'final solution' should not hinder West Germany from taking viewpoints which differ from Israel's positions or which even oppose these. The special relationship between Bonn and Jerusalem which is rooted in the terror of the Nazi past does not extend automatically to the terror of the Begin present."