Iran's new president was confirmed in office yesterday by Ayatollah Ruhollah Khomeini with a warning that there would be calls for his death if he betrays the Islamic revolution.

Pars, the official Iranian news agency, said government officials attended the ceremony for Mohammed Ali Rajai at Khomeini's residence outside Tehran. Pars said the Islamic leader reminded the new president, formerly premier, of his moral responsibilities.

"Should you put a foot wrong, the very 13 million who voted for you would shout, 'Death to you.' This is the nature of revolution," the news agency quoted Khomeini as saying.

At the same time, Khomeini said deposed president Abol Hassan Bani-Sadr could perhaps return to Iran in 10 or 15 years. Khomeini asked him to stop "discrediting" himself through interviews in his Paris exile.

Bani-Sadr was quoted as saying in an interview with the Sunday Times of London that he was counting on the armed forces which he led in battle against Iraq, to "do theirs duty" and end Khomeini's rule. He also was quoted as sasying the leftist Mujaheddin-e-Khalq underground organization could continue its assassination campaign against officials loyal to Khomeini throughout Iran, with parliament deputies the top targets.

Tehran radio reported that an unidenfitied gunman shot and killed Hojatolesalm Sheik Abdol Rahim Daneshju, a prominent cleric, Saturday night in the southern town of Kazerun.

Meanwhile, a military communique broadcast by Tehran radio said jets raided and destroyed 90 percent of an Iraqi oil pumping station and other oil installations to Tikrit, 100 miles northwest of Baghdad.