(Changes dateline to GUDERMES, rewrites throughout)
GUDERMES, Russia, April 16 (Reuters) - Rival pro-Russian forces in Chechnya faced each other in a tense standoff on Wednesday after a shootout that left several people dead.
Soldiers commanded by pro-Kremlin Chechen leader Ramzan Kadyrov clashed earlier this week with fighters supporting a rival pro-Russian commander in Gudermes, a town in the east of the mainly Muslim region.
Extra armed guards patrolled the president's residence on Wednesday and RIA news agency reported that law enforcement agencies were searching houses belonging to Sulim Yamadayev, the rival commander whose forces had fought Kadyrov's soldiers.
A witness living in Gudermes told Reuters on Tuesday at least 18 people died in the gunfight but other sources said several had been killed.
Russia fought Chechen rebels in two wars since 1994 which killed thousands and destroyed the republic. But the Kremlin says the war has ended and the region has stabilised with tiny groups of rebels holed up in the mountains.
Analysts said the battle between the two rivals shows the fragility of the situation in Chechnya, which the Kremlin says is one of President Vladimir Putin greatest achievements after eight years in power. Putin is due to step down next month.
Putin has relied on Kadyrov, a former rebel commander who expresses loyalty to the Kremlin, to rule the region. But Kadyrov's relations are tense with some other commanders and Russian special services who still operate in the region.
Kadyrov's forces clashed with fighters who support Yamadayev, commander of the elite Vostok (East) battalion, after vehicles in each convoy failed to give way.
"The situation came about when a cousin of Ramzan Kadyrov's drove at our soldiers at 190 kilometres an hour along the Gudermes road," Isa Yamadayev, a deputy in the Chechen national assembly and younger brother of Sulim Yamadayev, told Reuters.
He said Kadyrov arrived to calm the situation but tensions had risen when armed soldiers from both forces also sped into the area.
Nominally commanders of forces belonging to Chechnya's Interior and Defence ministries, Kadyrov and Yamadayev control private armies containing some of Russia's toughest soldiers, Moscow-based defence analyst Pavel Felgenhauer said.
The two forces have a long history of mutual distrust and dislike although their disputes are usually hidden from media. The gunbattle was not reported by most mainstream Russian television news programmes.
"This is more serious as it's out in the open and publicly embarrasses the Kremlin at a time when Putin is leaving and one of his achievements is being touted as making Chechnya peaceful once more," Felgenhauer said.
On Wednesday, the speaker of Chechnya's parliament called for Yamadayev to resign from his post as commander of the Vostok battalion.
RIA news agency said Interior Ministry officials were searching for weapons in houses in Gudermes belonging to Yamadayev's family. (Writing by James Kilner in Moscow; Editing by Mary Gabriel)