HAIKOU/GUANGZHOU, July 20 -- Two separate incidents where medical workers were taken hostage were handled by police on Monday, authorities said.

A nurse at the People's Hospital in Hainan Province was taken hostage for two hours Monday afternoon before she was rescued by police, the public security bureau of the provincial capital Haikou said in a press release.

It said the suspect, a man surnamed Tao, was holding a knife and threatened to attack anyone who approached him.

Tao was arrested by police at 3 p.m., when a woman journalist offered to replace the nurse as hostage. Police handcuffed Tao during the swap. No injuries were caused, the document said.

Tao's motive was unclear.

Police said Tao had been jailed once in Guangdong Province for his involvement in a melee that caused multiple injuries. He was released in 2012.

In another event at 9 a.m. Monday, a woman medical worker was taken hostage by a knife-wielding man at a hospital in downtown Guangzhou, local police confirmed.

The suspect, a 29-year-old man surnamed Zhang, was arrested by police after two hours of persuasion.

Zhang, from central China's Hunan Province, was allegedly unhappy with a report from the hospital, Guangzhou municipal public security bureau said in a statement.

It said the hostage was unharmed.

The well-being of China's medical workers has been under scrutiny recently. Apart from long working hours and an extremely heavy workload, doctors and nurses often fall victims to grumpy patients and family members.