Lao Mao, the head of Wuhancat Animal Rescue Center, estimates there are at least 20,000 to 30,000 animals trapped in and around Wuhan with no one around to feed them.

He told NBC News that 100 volunteers from the center had saved more than 2,500 such animals since the lockdown began.

Getting access to people’s homes is a challenge in itself in a locked-down city, he said.

Some pet owners have had to hand over pass codes from their digital locks, while others have asked volunteers to pick up spare keys elsewhere in the city. Some have even authorized locksmiths to let the volunteers in.