The man broke into the station and started randomly shooting with a machine gun, killing one and wounding two officers. The other officers in the station opened fire and killed him.
Lukac said upon arriving in Zvornik that "it was a terrorist act" and that "everything indicates that the attacker is linked to the Wahhabi movement," but that an investigation should establish if he had acted alone or as a member of an organised terrorist group.
The attacker was identified as 24-year-old Nerdin Ibric from Tuzla. Lukac told reporters "the first information gathered by the police... indicates that he publicly practiced radical Islam, including his conduct at prayer."
Lukac said the investigation would be taken over by the BiH Prosecutor's Office because the attack qualified as an act of terrorism. He called for keeping the peace, warning that the police would resolutely respond "to any revenge attempts. The police will prevent any more incidents."
The doctor who treated the two wounded officers, Miroslav Prodanovic, said their lives were not in danger. "According to the wounded policemen, it was a terrorist act. The attacker... was shouting 'Allahu Akbar' (God is greater)."
"I'm afraid this could be the beginning of much worse events in all of BiH," said Lukac.
RS President Dodik also said the attack was a terrorist act. He again accused the police and intelligence agencies at state level for not doing their job because they failed to provide any information about a possible attack, which "only indicates how many sleeper terrorists there are in RS."
Dodik said he was certain this was not an isolated act. "It's clear that it was an attack with religious and terrorist motives."
The motives of the attack are being investigated but Lukac said that security had been stepped up at all buildings that might be the target of similar attacks, including schools and kindergartens.
Security has been stepped up also by the directorate for the coordination of police bodies in BiH, which is in charge of protecting state institutions and diplomatic offices.
BiH Security Minister Dragan Mektic said intelligence from three days ago pointed to the possibility of a terrorist attack.
The media reported that the Intelligence and Security Agency (OSA) warned all police agencies in the country about the possibility of new attacks on police stations around BiH.
BiH Presidency Chairman Mladen Ivanic condemned the attack in strong terms, saying it was a terrorist act and that the state leadership would discuss the situation in the country at an extraordinary meeting.
"This act endangers the lives of ordinary people, the lives of our children. It's an attack on all of us and something on which there's no more compromise," he told reporters in Sarajevo.
Ivanic said he would demand an urgent meeting of representatives of all security structures in BiH because dealing with the threat of terrorism was the most important task for everyone in the country. "We can't, we mustn't and we won't let terrorism win because their wish is to create conditions for a new war. We will never give in to such things."
The BiH Council of Ministers is expected to discuss the security situation in the country on Tuesday.
The international community's High Representative to BiH, Valentin Inzko, called for not allowing new divisions in the country because of this latest crime. There is no more time to wait, he said. The attack on the police station in Bugojno in 2010 was a warning and this really should not have happened, he added.
After an extraordinary RS government session, RS President Dodik told reporters that OSA was responsible for the terror attack and that a special entity intelligence agency would be formed. He said it was "an outright lie" that OSA warned at the end of last week about the possibility of such an attack.
"It was general information about the possibility of an attack occurring in BiH, but that they (OSA) had no idea either where or who," he said, calling such information "ridiculous and useless."
Dodik said security was stepped up. "OSA is monitoring more what people in government are doing that dealing with terrorism," he said, adding that OSA had been "imposed by foreigners" and should be abolished. "Over the next three days we have to estimate the police capacities to confront terrorism. We will do what we have to and no one will stop us," he said.