The raid comes ahead of a mass demonstration in Seoul planned for Sunday by doctors, after the walkout, which began on Feb. 20, disrupted major hospitals, forcing some to turn away patients and cancel surgeries and other medical procedures.
"Doctors are enraged by the government's absurd behavior," the KMA, which represents private practitioners, said in a statement after the raid on the leaders of its emergency committee.
"The government has clearly shown that doctors in South Korea cannot enjoy freedom."
It denied having encouraged the trainee doctors to resign, saying they had left their posts of their own volition.
Health ministry data showed more than two-thirds of the trainee doctors, or nearly 9,000, had ignored a government deadline to return to work by Thursday or face punishment.
They are protesting against a plan to increase medical school admissions by 2,000 starting from 2025, which the government says is vital to remedy a shortage of doctors in one of the world's fastest-ageing societies.
The young doctors say they are overworked and underpaid, however, and the priority should be to improve their pay and working conditions instead.
Seoul police investigators raided the offices of five current and former KMA officials to collect evidence from their mobile telephones and computers, the Yonhap news agency said.
The health ministry told police this week of accusations that the officials had sought to obstruct business activity and were abetting the strike as well as defying the order to return to work, the agency added.
Police in the capital did not immediately respond to a request for comment.
During a visit to a veterans hospital in Seoul, Prime Minister Han Duck-soo pledged on Friday to ensure there was no disruption to services for veterans of the military.
The health ministry posted an order on its website urging 13 of the striking doctors to return to work or face criminal charges.
The government can order doctors back to work in case of grave risk to lives and public health.
Flouting such orders could lead to suspension of medical licences for up to a year, as well as three years in jail or a fine of 30 million won ($22,000).
($1=1,334.8500 won)
