Exiled Tibetan Buddhist leader, the Dalai Lama, told a meeting of scientists here that science must be guided by moral principles and decisions about how to apply science can no longer be left to individuals.

The Dalai Lama, on a 10-day visit to the US, raised some controversy by his speech Saturday at the annual convention of the Society for Neuroscience.

"It is no longer adequate to adopt the view that our responsibility as a society is to simply further scientific knowledge and enhance technological power and that the choice of what to do with this knowledge and power should be left in the hands of the individual," he said in a prepared text.

Some among the audience were upset over giving a religious leader such prominence at a scientific meeting. One woman on Saturday raised a placard that read "Dalai Lama not qualified to speak here", the Washington Post reported.

A petition opposing the group's speaking invitation to the Dalai Lama circulated on the Internet and got about 800 signatures, the Post said. Many of the petitioners were Chinese Americans, fuelling suggestions that the campaign was politically motivated.

China often objects to the Dalai Lama's travels and particularly meetings with foreign government leaders.

On Wednesday, the Dalai Lama met at the White House with US President George W. Bush, their third such meeting since 2001. He also met with US Secretary of State Condoleezza Rice.

A US State Department report on Tuesday criticized China's "poor" record on religious freedom and accused Beijing of suppressing Buddhism in Tibet.

The monastic leader is the author of a new book, "The Universe in a Single Atom: The Convergence of Science and Spirituality".

During his speech Saturday to 14,000 convention goers, he departed from his prepared text in both Tibetan and English, the Post said.

"It is all too evident that our moral thinking simply has not been able to keep pace with such rapid progress in our acquisition of knowledge and power," he said in the speech.

He specified that the "fundamental ethical principles" that he advocates for scientists were not an argument to meld science and religion.

"Rather, I am speaking of what I call secular ethics that embrace the key ethical principles, such as compassion, tolerance, a sense of caring, consideration of others, and the responsible use of knowledge and power," the Dalai Lama said. "Principles that transcend the barriers between religious believers and non-believers, and followers of this religion or that religion."