Zoom usage for meetings and school instruction has surged as a result of the coronavirus pandemic, but the video application has also seen an increase in harassment by hackers

Videoconferencing group Zoom pledged to step up privacy and safety controls after a series of complaints about the application which has surged in popularity during the coronavirus pandemic.

In a statement late Wednesday, Zoom founder and chief executive Eric Yuan said the company would be "shifting all our engineering resources to focus on our biggest trust, safety, and ."

Yuan said Zoom would work with third-party experts and users on a review "to understand and ensure the security of all of our new consumer use cases" and step up a "bug bounty" program to find .

The move came after the FBI highlighted the problem of "Zoombombing" by hackers or uninvited guests who harass Zoom video conferences with or pornography.

The FBI's Boston office warned on Monday that it had "received multiple reports of conferences being disrupted by pornographic and/or hate images and threatening language."

New York Attorney General Letitia James sent a letter to the California enterprise this week "with a number of questions to ensure the company is taking appropriate steps to ensure users' privacy and security," a spokesman said.

Yuan said he was "deeply sorry" for the incidents and pledged to work to fix the problems.

Zoom had some 200 million free and paid users in March as a result of the surge in usage around the world by people turning to remote meetings and school instruction as a result of the pandemic, he noted.

"During this time of isolation, we at Zoom feel incredibly privileged to be in a position to help you stay connected," he said in the statement.

"We also feel an immense responsibility. Usage of Zoom has ballooned overnight—far surpassing what we expected when we first announced our desire to help in late February. This includes over 90,000 schools across 20 countries that have taken us up on our offer to help children continue their education remotely," he said.