Serbian opposition leader Tomislav Nikolic left hospital and showed up at church for Easter Sunday mass, but it was not immediately clear whether he ended his week-long hunger strike demanding early elections.

Nikolic, 59, was seen at Belgrade's main Saborna church attending an Easter liturgy celebrated by the head of the Serbian Orthodox Church, Patriarch Irinej, broadcast live by the state-run RTS television channel.

No party official was available for comment on whether Nikolic, head of the right-wing populist Serbian Progressive Party (SNS), had ended his hunger strike.

The ruling coalition led by President Boris Tadic's Democratic Party has rejected the opposition demand for elections on December 18 instead of next May as scheduled.

Nikolic began taking liquids on Thursday following an appeal by Irinej, but he continued the hunger strike and said he would make any further decisions on Easter Sunday.

Local media have given prominent coverage to Nikolic's strike and deteriorating health, showing him lying on a sofa in parliament, and later in a hospital bed, pale and exhausted, with a crucifix around his neck.

He launched the strike at a rally of his supporters on 16 April and was hospitalised a day later.

The government insists that a vote should not be held until after a European Union decision on Serbia's membership application expected by the end of the year.

The government argues an election campaign before then could hamper the EU accession process.