Interfax news agency quoted a source close to the talks as saying a 14-point deal had been reached and RIA news agency quoted what it said was a rebel Twitter account saying an agreement had been signed.
The veracity of the account could not immediately be confirmed independently and a rebel leader, Vladimir Antyufeyev, todl Reuters he had no word yet from the separatists' representative at the talks.
Russian President Vladimir Putin said this week he had broadly agreed on steps toward a resolution of the conflict with Ukrainian President Petro Poroshenko and set out a seven-point proposal end to end the five-month-old conflict.
Poroshenko promised on Thursday to announce a ceasefire if the talks went ahead in Minsk.
Russian assets rallied on news that a truce had been reached. The rouble was slightly stronger against the dollar.