A man wielding a gun and a knife fatally shot one person and seriously wounded another at Poland's main opposition party Tuesday amid a desperately bitter, divisive election campaign.
Prime Minister Donald Tusk said the assault appeared to be politically motivated and appealed for calm, urging all political parties to make sure "violence does not become a method in the political struggle."
"Everything suggests that the motivation was of a political nature," Tusk said, called it a "tragic, senseless assassination" and an "attack of a madman."
Opposition leader Jaroslaw Kaczynski accused Tusk, his main rival, of instigating the attack early Tuesday at a Law and Justice party office in the central city of Lodz.
"The events that took place are the result of a huge hate campaign that has been waged against Law and Justice for a long time," Kaczynski told reporters.
Kaczynski's conservative party is the second most popular in Poland, after Tusk's liberal Civic Platform.
Police disarmed and detained 62-year-old Ryszard C., who they said traveled from his home in the southern city of Czestochowa four days ago to plot the Lodz attack.
In TV footage of the arrest, the gray-haired attacker could be heard saying he "wanted to kill Kaczynski."
"I am against (Law and Justice) and wanted to murder him," the attacker said.
The attacker opened fire, killing Marek Rosiak, 62, an aide to a Law and Justice member of the European parliament. Next he began stabbing Pawel Kowalski, 39, who remained hospitalized with serious wounds.
The attack came as the nation's two main parties fight for supporters ahead of local elections next month, the first local vote since Kaczynski's twin brother, President Lech Kaczynski, was killed with many top officials in an April 10 plane crash.
The tragedy aggravated long-standing divisions in Poland between pro-European Union citizens, who back the government, and more conservative, deeply faithful Roman Catholic Poles who support Kaczynski and blame the April 10 plane crash that killed 96 people on the government.
In 1922, political dispute was blamed for the murder of first post-World War I president of a democratic Poland, Gabriel Narutowicz.