The militants occupying the U.S. Embassy Sunday invited a delegation including Red Cross representatives to visit all of their American captives as Iran faced a collective Western protest about lack of progress on the hostage issue.

It was not immediately clear, however, whether the Moslem student captors would fully agree to Red Cross conditions for the visit, tentatively scheduled for Monday afternoon. The Red Cross representative here said an "agreement in principle" had been reached, but that the visit hinged on the militants' confirmation of the accord upon his arrival at the embassy.

Meanwhile, the envoys of eight European Common Market countries and Japan were being recalled for consultation to their capitals to protest the failure of Iranian leaders to heed their appeal for the hostages' release, diplomatic sources said.

[Most of the eight European envoys had left or were preparing to leave by midmorning Monday, with the others and the Japanese envoy to leave Tuesday.]

In continuing efforts to rally support for Iran's position in the hostage crisis and its conflict with neighboring Iraq, Foreign Minister Sadegh Ghotbzadeh conferred Sunday with the chiefs of mission of the Islamic countries and said he may also hold discussions with African and East European envoys.

The militants said Sunday that they would allow the Red Cross team to "see all the hostages." If this promise were made good, it would be the first time since the Nov. 4 embassy takeover that all the captives were seen by an independent foreign observer.

So far, independent observers have only seen 46 of the hostages, leaving in question the fate of four more hostages that the State Department says are being held. Rumors have circulated that several of the hostages denounced by their captors as spies may have been transferred elsewhere and that one hostage may have attempted suicide or been otherwise harmed.

Arousing special concern has been the fate of embassy political officer Michael J. Metrinko, who has not been seen by an outside observer or heard from in any letter to his family.

While agreeing that all the Americans can be seen, the captors hedged on whether they would meet other conditions put forward by the Red Cross for all visits it undertakes to prisoners and other detainees. These conditions are that each detainee must be seen individually in his place of detention, that there be no other observers present while he is being interviewed and that he be allowed to fill out a Red Cross questionnaire in private.

A spokesman for the militants said Sunday night that he did not know whether the hostages would be presented to the visitors individually or in groups. Asked whether the militants would permit private interviews with the captives, the spokesman said, "I doubt if that has been decided."

Reflecting the militants' obsession with secrecy, the spokesman refused to say who would decide these questions. "We know what we do inside and we don't need to tell anybody," he said angrily.

The militants' decision to invite a delegation to see the hostages follows an edict last week by Iran's revolutionary leader Ayatollah Ruhollah Khomeini authorizing more visits to the captives after three American clergymen sympathetic to the militants held Easter services inside the occupied embassy.

In addition to Red Cross officials, the militants Sunday invited Iran's health minister, Dr. Musa Zargar, the leader of Tehran's Friday prayers, Hojatoleslam Mohammed Ali Khamenehi and representatives of the Red Lion and Sun Society, Iran's equivalent of the Red Cross.

A Red Lion and Sun Society doctor was admitted to the embassy last month and gave cursory examinations to several hostages. Television film shot under the supervision of the militants showed 11 hostages being examined by the doctor, who was erroneously identified as a Red Cross representative. The film was made available to American television and caused concern when several of the hostages appeared to be suffering depression or mental stress.

Harold Schmidt de Grueneck, the Swiss representative in Tehran of the Geneva-based Red Cross, said in a telephone interview Sunday: "I gave them [the militants] my conditions, and the visit has been agreed to in principle." He added, however, that the final go-ahead awaited confirmation by the militants that the conditions would be represented.

De Grueneck said a Swiss doctor, Bernard Liebeskind, flew in from Geneva to participate in the anticipated hostage visit.

"I have been working on this since the very beginning," De Grueneck said. He said he saw about 15 hostages during a previous visit in November with a delegation of diplomats but was unable to interview the captives in accordance with Red Cross regulations.

Western diplomats here were taking a cautious attitude toward the militants' invitation. Some expressed skepticism that, even if the Red Cross representatives went into the embassy with a firm agreement on conditions, the militants would abide by the rules once the visit began.

"I'll believe it when I see it," said one European diplomat. "Besides, there is a point when you have to stand back and say, 'its disgraceful that after more than five months all that has been agreed is a visit to the hostages.'"

Another senior European envoy, referring to the Common Market countries' decision to recall their chiefs of mission, said a hostage visit "would be good, but we're leaving anyway."

He added bitterly, "We've been sitting around for too long.It's high time the Iranians realized that the rest of the world just doesn't believe what they say. If things get better, then maybe we will come back. If they don't, maybe we'll move on to other measures."

He would not elaborate on what the other measures might be, but the implication was European participation in economic sanctions.

The Europeans' frustrations were reportedly made clear to President Abol Hassan Bani-Sadr during a meeting Saturday with the chiefs of mission representing the nine-member European Community and Japan.

The eight European envoys scheduled to leave Monday represent Britain, France, West Germany, Italy, Belgium, Ireland, the Netherlands and Denmark. The ninth Common Market member, Luxembourg, does not maintain an embassy in Tehran.

Another European diplomat, the Norwegian envoy, left Iran a week ago for Pakistan and is being recalled to Olso instead of returning here in light of the hostage situation diplomatic sources said.

The tough statements on the hostages crisis by some European diplomats appear to contrast with their countries' reluctance to join U.S. political and economic sanctions against Iran. Some observers here interpreted the statements as jawboning to elicit some Iranian response before the European countries come under pressure to join the sanctions.

After his meeting with Moslem envoys, Ghotbzadeh said he had explained his government's stand in its crisis with the United States and Iraq.

"We pointed out the Iraq is the mainagent of imperialism in the area and by itself is nothing," Ghotbzadeh said.

His statement came amid conflicting reports on clashes at the Iranian-Iraqi border.

A communique by the 81st Armored Division based in western Iran said Iraqi forces opened artillery fire on the area of Baveissi and that Iranian units returned the fire. The statement said two Iranian solders "reached the rank of martyrdom in the course of the operation" and that the enemy "suffered heavy casualties."

However, Gen. Hadi Shadmehr, chief of the armed forces joint staffs, said that some field officers, particularly those in the Revolutionary Guard, issue statements independently "and in some instances exaggerate somewhat in giving reports."

Apparently seeking to assess the situation, Bani-Sadr Sunday left Tehran for the western border on his way to tour development projects in the oil-producing province of Khuzestan.