Live Updates: Suspect Is Charged in Attempted Killing of Slovakia’s Leader

Officials have not identified the assailant, but they said the attack appeared to be politically motivated. The suspect, who was identified as a “lone wolf,” has been charged with premeditated murder.

On Thursday, Zuzana Caputova, the country’s departing president, stressed that the attack was an “individual act” and said she would invite leaders from Slovakia’s main political parties to meet in order to “calm down the situation.”

“We have difference of opinions, but let’s not spread hatred,” she said in a statement alongside the president-elect, Peter Pellegrini.

Mr. Pellegrini echoed her appeal to tone down escalatory rhetoric while also calling on the country’s political parties to temporarily pause or “calm down” their campaigns for next month’s European Parliament elections. Campaigns, he told a news conference, naturally involve confrontations and “strong opinions.”

“We do not need more confrontation,” he said, adding that “civilized discussion” was critical before the polls.

Amid questions about the response of Slovak security forces to the shooting, Michal Simecka, the chair of the opposition Progressive Slovakia party, expressed confidence that the authorities would carry out “a thorough investigation of their actions.”

“Instead of blaming each other, today we especially need to reduce tension and polarization in society, create space for the investigation of this terrible act,” he wrote on social media.

He later welcomed Mr. Pellegrini’s suggestion of pausing campaigning for the European Parliament elections, saying that his party had done so and would do everything it can to help “calm the situation” in Slovakia.

The police, who had asked news outlets and social media users to turn off comments on articles and posts about the attack, said they were monitoring online activity. Some comments have condoned the violence against Mr. Fico, the police said on Facebook on Thursday, adding that if police action were needed, it would be taken.

Slovakia’s often venomous divisions have been fed by its particularly noxious online ecosphere, where politicians have gained large followings with intemperate attacks on domestic critics and Western leaders.

Mr. Fico returned to the premiership last year, defying expectations after his Smer party narrowly won a bitterly contested legislative election.

After the shooting, politicians across the political spectrum pointed fingers at one another. Lubos Blaha, the vice chairman of Smer, said the opposition and what he called “the liberal media” had “built a gallows” for the prime minister by “spreading so much hatred.” Rudolf Huliak, an ally of the government from the far-right Slovak National Party, said progressives and journalists “have Robert Fico’s blood on their hands.”

Slovakia’s political temperature has risen to fever pitch in recent months as Mr. Fico’s government has pushed for an overhaul of the country’s state broadcasting system to purge what it sees as liberal bias and crack down on nongovernmental organizations it views as agents of foreign meddling.