* Kiev to send new special forces to control Odessa
* Slams police after pro-Russia activists freed
* Pro-Moscow groups see Kiev promoting "fascist" groups
* Fighting continues in eastern city of Slaviansk (Adds detail throughout)
By Oleksander Miliukov
ODESSA, Ukraine, May 5 (Reuters) - Ukraine's Interior Minister drafted a new special forces unit into the southern port city of Odessa on Monday after what he called the "outrageous" failure of police to tackle pro-Russian separatists in a weekend of violence that killed dozens.
Fighting continued near the eastern town of Slaviansk where Ukrainian troops have been, somewhat tentatively, pressing a campaign to end pro-Russian rebellion. A Reuters correspondent said gunfire seemed to be coming closer to the city centre.
The violence in Odessa, a southwestern port with a broad ethnic mix from Russians and Ukrainians to Georgians and Tatars, was seen as a turning point in Kiev, encroaching for the first time into an area beyond the Russian-speaking east.
Authorities fear trouble in Kiev in the approach to Friday's celebrations of the Soviet victory in World War Two.
Interior Minister Arsen Avakov said the new Odessa force, "Kiev-1", was based on "civil activists" who wanted to help the Black Sea city "in these difficult days". The leadership of the local police had been fired and may face criminal action.
Friday's fighting in Odessa was the deadliest since Moscow-oriented president Viktor Yanukovich fled to Russia in February and pro-Russian militants launched uprisings in towns across the industrial east. Over 40 people were killed and Ukraine, a country of 45 million, appeared to be lurching to civil war.
"The police in Odessa acted outrageously, possibly in a criminal fashion," Avakov wrote on his Facebook page. "The 'honour of the uniform' will offer no cover."
Ukrainian leaders have made it clear they see the police force across wide areas of the country as unreliable in the face of rebellion they say is backed by Moscow and led on the ground by Russian special forces. The units Avakov referred to emerged partly from the uprising against Yanukovich early this year.
That could fuel anger among the government's opponents, who accuse it of promoting "fascist" militant groups, such as Right Sector, that took part in the Kiev uprising over the winter.
ODESSA'S ECONOMIC IMPORTANCE
Loss of control of Odessa would be a huge economic and political blow for Kiev, Ukraine, a country the size of France that borders several NATO countries and harbours aspirations to join the alliance, a primary source of concern for the Kremlin.
Odessa, a city of a million people, with a grand history as the cosmopolitan southern gateway for the tsars' empire, has two ports, including an oil terminal, and is a key transport hub.
It would also heighten Western concern that Ukraine, already culturally divided between an industrial, Russian-speaking east and a more westward looking west, could disintegrate. As well as humanitarian problems that could entail, neighbouring NATO and EU countries would face a deep crisis in relations with Moscow, which supplies much of Western countries' energy via Ukraine.
Kiev's anger on Monday focused on the Odessa police decision to release 67 largely pro-Russian militants after supporters besieged and stormed a police station on Sunday. Russian is the first language of many of the city's residents.
The pro-Russian activists had been arrested on Friday after hours of street fighting. Other pro-Russian supporters withdrew to a building that later burned down with the loss of over 40 people - bloodshed that Moscow blames on Kiev's "provocations".
The exact circumstances of the blaze remain unclear but the deaths have become a cause celebre for anti-Kiev activists across the south and east.
The chant "Odessa is a Russian city!" was heard at pro-Russian demonstrations through the weekend.
Dissected by tree-lined boulevards and elegant, Mediterranean classical architecture including a neo-Baroque opera house in the Viennese style, Odessa is viewed by many Russians as just that. It was founded by Empress Catherine the Great and played a key role in Russian imperial history.
Soviet film director Sergei Eisenstein set scenes of a massacre of civilians during a 1905 uprising on the grand steps that sweep down to the port. The images from "The Battleship Potemkin" are among the most famous in cinema history.
DIPLOMACY
Odessa was generally quiet on Monday, while funerals went ahead for people killed in Friday's clashes. But in the east, clashes continued.
Pro-Russian separatists ambushed Ukrainian forces, triggering heavy fighting on the outskirts of the rebel stronghold of Slaviansk, Interior Minister Avakov said.
A Reuters correspondent said at least two separatist armoured personnel carriers and several rebels fled the area, where almost continuous gunfire had been heard since morning.
"In the morning, a squad in the anti-terrorist operation was hit by an ambush by terrorist groups. They are using heavy weapons," Avakov was quoted as saying near Slaviansk by Interfax-Ukraine news agency.
He said there were deaths on the Ukrainian side but did give a figure. The regional administration in Donetsk said the fighting had halted bus services to various towns.
Ukraine's defence ministry said the army had freed a pilot captured by separatists after his helicopter was shot down near Slaviansk on Friday. The Interior Ministry said armed men had seized police offices in the eastern town of Slovianoserbsk.
Diplomacy continued over the weekend.
Germany said on Sunday it was pressing for a second meeting in Geneva to bring Russia and Ukraine together with the United States and European Union. Moscow and Kiev accuse each other of wrecking an earlier accord on April 17.
Berlin said on Monday it was doing what it could to make sure a presidential election planned for May 25 went ahead.
"The election would be not just a means for stabilisation but also a strong signal for a better future for Ukraine," Chancellor Angela Merkel's spokesman Steffen Seibert said.
He said a referendum planned by pro-Russian separatists in the eastern city of Donetsk, where rebels have proclaimed a "Donetsk People's Republic", would increase tensions.
Certainly, failure by Kiev authorities to conduct the election in rebel-controlled eastern cities would give Moscow grounds to question the legitimacy of any government emerging, just as it challenges the present administration. (Additional reporting by Ralph Boulton, Natalia Zinets and Elizabeth Piper in Kiev, Maria Tsvetkova in Slaviansk and Matt Robinson in Donetsk; Writing by Ralph Boulton; Editing by Alastair Macdonald)
Our Standards: The Thomson Reuters Trust Principles.
