World leaders Wednesday mourned the death of former Indian Prime Minister Rajiv Gandhi and condemned his assassination as an attack on his nation's democratic system.

Some worried that Gandhi's death in a bomb blast Tuesday could lead to greater instability and bloodshed in the world's most populous democracy."A stern trial of character and will may now face India, her leaders and her people," U.N. Secretary-General Javier Perez de Cuellar said Tuesday in a message to Gandhi's widow, Sonia. "They will have the goodwill of the entire international community in facing this challenge."

Prime Minister John Major of Britain called Gandhi "a very brave man" and said that despite the loss he remained optimistic about India's future. "Democracy is a very secure plant, and I have no doubt it will survive."

France's new premier, Edith Cresson, called the assassination a "great misfortune for democracy."

President Bush denounced the killing as "appalling," and the House of Representatives observed a moment of silence.

"I don't know what the world's coming to," Bush said.

Sen. Daniel Patrick Moynihan, D-N.Y., ambassador to India from 1973-75, said, "The world has lost a great democratic leader." He added: "You can blow up a leader; you cannot blow up a democracy."

President Mikhail S. Gorbachev of the Soviet Union said his country was "filled with indignation over this monstrous crime."

Britain's Queen Elizabeth II sent a message to Indian President Ramyswami Venkataraman saying, "As head of the Commonwealth I mourn the loss of a man of stature and courage. I send you and all those affected by his death my heartfelt sympathy."

Vice President Dan Quayle said in Jakarta, Indonesia, Wednesday that he will fly directly to India to represent the United States at Gandhi's funeral. The Indian politician is to be cremated on Friday.

In Pakistan, India's neighbor and longtime rival, Prime Minister Nawaz Sharif said he was stunned by Gandhi's death.