* Chechen leader says to fight insurgents in Ingushetia
* Ingush politicians warn of chaos if Kadyrov gets control
* Kadyrov vows revenge while on surprise visit to Nazran
NAZRAN, Russia, June 24 (Reuters) - Chechen leader Ramzan Kadyrov made a surprise visit to the neighbouring Russian region of Ingushetia on Wednesday and vowed to exact revenge for a suicide attack which gravely wounded its president.
Ingushetia, which shares a common culture with Chechnya, has become one of the most unstable spots along Russia's turbulent southern flank and Monday's suicide bombing has underlined the Kremlin's fragile grip over the region.
Just hours after the attack on Ingush President Yunus-Bek Yevkurov, Kadyrov told Reuters he had been ordered by the Kremlin to fight insurgents in Ingushetia. [ID:nLN714144]
His comments provoked speculation that Kadyrov was seeking to widen his clout over neighbouring regions in the North Caucasus. Ingush politicians warned such a move could tip the region further into chaos.
"We will conduct our investigation in line with the law of the mountains and our revenge for Yunus-Bek Yevkurov will be ruthless," Kadyrov was quoted as saying in the local capital, Magas, where he met acting Ingush president Rashid Gaisanov.
The statement indicated Kadyrov was referring to the region's ancient tradition of blood feuds. Ingush officials said Kadyrov's visit had been a surprise.
Security forces say Ingushetia provided a foothold for global networks of Islamist militants, but locals say the insurgency has its roots in poverty, corruption and heavy-handed tactics by local rulers.
Yevkurov, a highly decorated ex-paratrooper who took control of Pristina airport in Kosovo in 1999 after the NATO bombing of Yugoslavia, was appointed in October by Kremlin chief Dmitry Medvedev to calm the region after Murat Zyazikov, a former KGB officer, had been leader.
Under Zyazikov, violence in Ingushetia rose sharply.
Ingush politicians lined up on Wednesday to dismiss Kadyrov's idea of taking a bigger role in Ingushetia, which was lumped together with Chechnya in Soviet times.
"I think adding additional neighbouring forces would further entangle the situation there," Ruslan Aushev, who ruled Ingushetia from 1992-2001, told Echo Moskvy radio station.
"If they want to complicate the situation then this is what you do," said Aushev, one of Ingushetia's most influential politicians. Aushev added that he would be willing to take over the reins of government while Yevkurov was nursed back to health.