Reports of heavy fighting on the #Slovyansk outskirts today. Unconfirmed vid of huge explosion seen there https://t.co/enTcUYmDaF
— Maxim Eristavi (@MaximEristavi) May 5, 2014
Ukraine formally closes border checkpoints in occupied Crimea. Russian media reports: "Ukraine seals off its border".
— Leonid Ragozin (@leonidragozin) May 5, 2014
Ukrainian Interior Minister Arsen Avakov was quoted as saying that there have been "deaths" as troops fight pro-Russian militants who control the city.
Rebel forces were reportedly withdrawing toward the center of the city after government forces took control of a television tower in the southern suburb of Andreyevka.
Slovyansk, a city of some 140,000 is one of a string of cities in eastern Ukraine controlled by pro-Russian rebels.
The government has vowed to continue an "antiterrorist" operation until it regains control.
Acting President Oleksandr Turchynov has said Russia "is at war" with his country.
Russia denies the Ukrainian government's accusations that it is fomenting violence in southern and eastern Ukraine.
horrible photos of those burned in #Odessa http://t.co/569XhsWdLo. notice some were shot and others were lying in rooms untouched by fire
— Kateryna_Kruk (@Kateryna_Kruk) May 5, 2014
Centre of #Slovyansk. All quiet for the past 30 mins pic.twitter.com/UtT0oYItQ8
— Will Vernon (@BBCWillVernon) May 5, 2014
#Slovyansk Heavy rain now in city. Sitting with pro Russia rep who says "we fighting,we defending"
— Fergal Keane (@fergalkeane47) May 5, 2014
#Slovyansk Picture v unclear. Lots of armed men. Clearly much of town still in rebel hands
— Fergal Keane (@fergalkeane47) May 5, 2014
Russia to appeal to UN to delay election in Ukraine (no mention of delaying the referendum!) http://t.co/OsCVT47hmJ via @ria_novosti
— Daniel Sandford (@BBCDanielS) May 5, 2014
4 Interior troops killed in gunfight w/ pro-Russian separatists in #Sloviansk, casualties among local pop -@MVS_UA_ru http://t.co/xUPeoDoKfA
— Christopher Miller (@ChristopherJM) May 5, 2014