Kulov mentioned Aitbaev by name, and then followed up today by accusing the National Security Service of ineffectiveness.
"The Security Service needs to be a national security service and not an organization that shelters criminals -- in which there is a criminal," Kulov said. "They should occupy themselves with intelligence and counterintelligence, the greater problems of providing security."
Security Service chief Aitbaev responded angrily in an address to parliament.
"I must defend my honor and dignity," Aitbaev said. "Honorable deputies, let [Kulov] produce one fact. I am ready to answer before you. I'm ready to answer before the president, before anyone. I declare that I have no involvement in...these [illegal] events. Mr. Kulov named as an example [of corruption] Aitbaev, and you know why. He said things against me on the first day he became prime minister. He set the tone. But I believe that I don't need to let bad personal relationships affect the work of the government, and I have never done so."
Kulov's public barrage follows high-profile events that have prompted concerns about the independence of the courts and the central government's ability to maintain order.
On 24 January, a court acquitted of murder charges a man whom some regard as a criminal kingpin. Kulov said the decision "inflicted a heavy blow to our international image."
The acquitted man, Ryspek Akmatbaev, countered by noting that Kulov was himself jailed for corruption and abuse of office when Askar Akaev was president. Akmatbaev accused the prime minister of pursuing a hidden agenda.
"After what Kulov said yesterday, I must say that this is [political] intrigue," Akmatbaev said. "He doesn't even know what he is talking about because all of us know how he worked before under Akaev."
The central government has also had to confront challenges at the regional level. Last week, the governor of the southern Jalal-Abad Province defied a presidential transfer to another province, and his supporters staged a series of protests. The governor eventually flew to Bishkek to meet with President Kurmanbek Bakiev -- and afterward claimed political victory.
Lawmaker Melis Eshimkanov told RFE/RL that -- in the light of recent events -- Kulov's comments were hardly surprising. He also said he tended to agree.
"It wasn't unexpected for me at all, because our society wants to know Feliks Kulov's opinion on recent events," Eshimkanov said. "There are dismissed governors in the Talas and Jalal-Abad regions continuing their work, yesterday a Security Service officer [who was] arrested with weapons and drugs in his possession was freed, and other events show that the postrevolutionary situation in Kyrgyzstan is still very unstable."
Independent political analyst Toktagul Kakchekeev conceded Kulov's general argument. He was blunt in his criticism of the National Security Service, saying it has failed to combat crime and is now hindering his efforts to fight criminal organizations.
"Because the National Security Service is directly under the control of the president, they do what they want and do not do those things for which they have no desire," Kakchekeev said. "They are like a spoiled child. They are responsible for the alarming situation in the country. From Kulov's statement, I understood that he cannot exercise his authority and he needed to say these things openly to the public."
The president, Kurmanbek Bakiev, vowed to eliminate corruption and criminal influence in politics when he was campaigning for president in mid-2005.
Tired of waiting for stronger action from the office of the president, Prime Minister Kulov appears to be seizing the political initiative. Today's parliamentary vote suggests he has some support.