"Peace is at hand," was the catch-phrase Monday at Boston University (B.U.). By Thursday, the elusive peace had been shattered and B.U.'s faculty, clerical workers and librarians were all on strike.

After months of arduous negotiations, exacerbated by harsh charges and counter-charges, negotiators for both sides finally reached agreement on a contract Saturday. The faculty approved the contract by a 252-17 vote Monday, and the trustees were expected to follow suit the next day.

The 46-member board of trustees, however, withheld final approval of the contract pending clarification of several sections it called ambiguous. Ameeting between trustees and faculty representatives on Wednesday failed to resolve the differences, and that evening the executive board of the faculty union called a strike for the next day.

Most of the 800 faculty members represented by the union participated in the strike Thursday and Friday, and each side accused the other of aggravating the dispute. Arthur G. B. Metcalf, chairman of the board of trustees, said Wednesday a faculty decision to strike would negate the agreements already reached (including any raises), but administration spokesmen backed off that statement yesterday.

The faculty are joined in the strike by a clerical workers' union, representing 900 employees, and by a union representing 20 librarians. The librarians and clerical workers are seeking recognition by the university; the faculty is demanding salary increases and more input into the university's decision-making processes.

Spokesman for both the faculty and the administration said yesterday they want the dispute to be settled soon and hoped a final agreement would be reached during meetings over the weekend.