One of the two key Kyrgyz leaders to emerge from last week's coup, Felix Kulov, resigned on Wednesday as security chief, triggering concerns a split was already developing in the Central Asian state's new leadership. And underscoring fears that impoverished Kyrgyzstan could reignite into violence, acting President Kurmanbek Bakiyev urged ousted leader Askar Akayev not to return from exile in Russia, saying the country was still too unstable. "I would advise him not to come because his return is not expedient at the moment. Passions have not yet died down," Bakiyev said on national television, fielding questions from viewers. "If he decided to return in the short term, then it could spark unrest not only in (the capital) Bishkek, but throughout the republic." Akayev, who led the ex-Soviet state for 14 years until he fled in the face of violent opposition protests last Thursday, said he was ready to come home if his safety was guaranteed and would work with parliament to ensure a legitimate change of power. He won that guarantee from Kulov early on Wednesday. But within hours, Kulov had resigned, giving as his reason the fact the country was back to normal. "With God's help, order was formed, ministers were appointed and everything has returned to a constitutional framework ... Once the government was formed the need for me to be there disappeared," Kulov said. "There are no reasons (for stepping down) other than this." But a close Kulov associate told Reuters he had quit after Bakiyev appointed one of his own allies as head of the national security service without consulting Kulov. The acting president also put as deputy head of the security service a person involved in an investigation into Kulov, who was jailed for embezzlement during Akayev's rule. --More 2343 Local Time 2043 GMT