Serbian officials called on Thursday for urgent measures to combat widespread domestic violence in the country following the killing of two women and a child at social-care centers in Belgrade this month.

Activists warned that the incidents have exposed problems in Serbia's protection system. There are reports that 22 women have been killed by their husbands or partners this year.

On Wednesday, a man killed his ex-wife and son and wounded three social workers just outside a social-care center. Last week, a man killed his wife with a stone in front of their three children in another center.

Social care minister Zoran Djordjevic said "we must sound the highest alarm" and announced further efforts after a new, tougher law recently took effect.

"We will try to come up with concrete wholescale preventive measures for the coming period," said Djordjevic. "We must all act to fight this, the situation is alarming."

Authorities said measures will include installing panic buttons in 60 social-care centers. Social workers have threatened to go on strike unless security is beefed up.

Serbia's President Aleksandar Vucic said during an official trip to Greece that he will demand stricter punishments in domestic violence cases.

"Family violence is frightening," Vucic said, according to Serbia's state TV. "Those men must be punished most drastically and dramatically so they never think of doing it again."

Domestic violence in the conservative Balkan country has soared since the wars of the 1990s.

Tanja Ignjatovic, from the Autonomous Women's Center rights group, told N1 television that the latest incidents were the result of "classic system failure."

"It can't be in the interest of children to have contact with a parent who was violent to their mother or the children themselves," Ignjatovic said.