An online petition initiated by Chinese internet users for a thorough investigation of a biological laboratory at Fort Detrick in the United States concluded on Friday, garnering 25 million signatures in just three weeks.

The petition, which a group of Chinese internet users drafted and entrusted the Global Times to post on social media, was launched on July 17 and received 500,000 signatures in 24 hours and 1 million in 48 hours. It concluded at midnight on Friday Beijing time.

The investigation should look at the origins of COVID-19 as related to the Maryland laboratory as well as the laboratory's safety, the organizers said.

Dangerous infectious viruses are stored at Fort Detrick, 80 kilometers northwest of Washington, and there was a leak there in 2019, just before the pandemic broke out, the Global Times said.

As the number of signatories to the petition neared 10 million, the website was subjected to severe cyberattacks whose origins were IP addresses in the US, the newspaper said.

Chinese Foreign Ministry spokesman Zhao Lijian said on July 26 that the US needs to explain why it remains silent on opening the Fort Detrick laboratory to an investigation and why it launched cyberattacks on the website housing the petition, which calls for the World Health Organization to investigate the laboratory's activities.

A Weibo user said: "China won't take the blame and be the scapegoat for the US' egregious mishandling of the COVID-19 pandemic. The US has the most confirmed cases and deaths in the world, yet it has barely done anything good to the international community in fighting the pandemic."

Another Weibo user, dorelaK, said investigating only one US biological laboratory is insufficient, calling for that all such laboratories, of which there are more than 200 worldwide, to be investigated.

On Thursday a group of Filipino academics, along with Herman Laurel, a political commentator, launched an online petition similar to the Chinese one calling for "the wall of silence" to be broken regarding Fort Detrick.

The campaign, which has amassed hundreds of signatures, also calls on "certain countries" to stop politicizing COVID-19.

Calling on the WHO to investigate Fort Detrick, Laurel, a columnist for the social news website Sovereign PH, said the laboratory "suffered a laboratory incident in July 2019, causing the US Centers for Disease Control to shut down the facility (the following month) due to 'serious safety violations'".

Xinhua contributed to this story.