Police Minister Fikile Mbalula's threat to "nail" and "outgun" criminals is worrying, Democratic Alliance (DA) MP Zakhele Mbhele said on Tuesday.

"It is unacceptable that these men, who can so glibly utter such thoughtless and dangerous statements, can be trusted with the safety and security of millions of South Africans."

He was responding to remarks Mbalula made at a police parade, in Pretoria, to welcome him and his deputy Bongani Mkongi.

The former sports and recreation minister told police to be merciless in their fight against crime.

"We must not smile with heavily armed and dangerous criminals. We must nail them, we must be merciless," Mbalula said.

"We are tired of burying crime fighters. Anyone who kills a policeman will meet fire with fire. No policeman will die in vain. If they come with AK-47s, we must outgun them! Meet fire with fire," the fiery minister said.

However, it had to be done within the confines of the law, he pointed out.

Mbhele said such comments were reckless and could lead to a loss of life. Mbalula and Mkongi were unfit to lead the department and did not represent the interests of ordinary South Africans.

"Both have expressed troubling views on the use of violence, and how the people of South Africa can and should be treated," Mbhele said.

"Mbalula and Mkongi would rather revel in pomp and ceremony at a parade to honour their egos than get down to the very serious business of ensuring that SAPS members have the equipment, training and resources they need to make South Africa safe."