LONDON -- Unfounded allegations by some US politicians that the COVID-19 virus escaped from a Chinese lab are making it harder for nations to collaborate on ending the pandemic, and fueling online bullying, said a recent article in British scientific journal Nature.

"Even without strong supporting evidence," calls to investigate Chinese laboratories have reached a fever pitch in the United States, said the article, adding that for many researchers, the tone of the growing demands is unsettling, which could thwart efforts to study the virus's origins.

While some US politicians groundlessly allege that the coronavirus causing the pandemic was leaked from a Chinese lab, scientists argue that the hypothesis requires a thorough, independent inquiry, said Nature.

Citing some scientists, the article said, "the rhetoric around an alleged lab leak has grown so toxic that it's fuelling online bullying of scientists and anti-Asian harassment in the United States, as well as offending researchers and authorities in China whose cooperation is needed."

The article noted that to curb the pandemic and prepare the world for future outbreaks, actions, include expanding the distribution of vaccines and reforming biosecurity rules, are needed.

"But such measures require a broad consensus among powerful countries," Amanda Glassman, a global-health specialist at the Center for Global Development in Washington, was quoted as saying.

"We need to look at the big picture and focus on incentives that get us where we want to go," she said. "A confrontational approach will make things worse."

The escalating demands and allegations are contributing to a geopolitical rift at a moment when solidarity is needed, said David Fidler, a global-health researcher at the Council on Foreign Relations, a US think tank.