MANILA — Rights advocates and survivors of the dictatorship of Ferdinand E. Marcos, the former Philippine leader, criticized President Rodrigo Duterte on Monday for saying that he could impose martial law to curb what he has called a runaway drug problem.

Duterte has made the war against illicit drugs a focus of his administration. On Saturday, in a speech to business leaders, he warned that if the drug problem deteriorated into “something really very virulent, I will declare martial law,’’ adding “No one can stop me. My country transcends everything else, even the limitations.’’

More than 6,000 killings across the Philippines have been linked to the anti-drug campaign that began after Duterte took office in June. About 2,200 happened in encounters with police, according to the National Police. The rest are classified as “deaths under investigation,’’ including those carried out by unknown vigilantes.

“He has fascist dreams,’’ Loretta Rosales, 77, a former chairwoman of the Commission on Human Rights of the Philippines, said of Duterte. She was tortured under Marcos, who was elected president in 1965 and imposed martial law from 1972 to 1981. He was forced from power in 1986.

“As a martial law victim and survivor, I detest his martial law threat,’’ Rosales said. “This is clearly meant to establish authoritarian rule to enforce his goals . . . and he is happy to slaughter three million Filipinos to do this,’’ she said.

She was alluding to Duterte’s statement in September comparing his anti-drug campaign to the Holocaust; he said he’d kill drug addicts by the millions, as Hitler killed Jews.

Ramon C. Casiple, a political analyst and executive director of the Institute for Political and Electoral Reform, a nongovernmental organization, said there was no “basis for declaring martial law’’ and that Duterte could not do so “unless he can convince people that there is a serious threat of rebellion or foreign armed intervention.’’