A march was held in Pale for Mr Karadzic, who faces genocide charges
Thousands of supporters of the former Bosnian Serb leader, Radovan Karadzic, have held protests over his arrest to face the war crimes tribunal.
Demonstrations were held in across the Serb part of Bosnia, the biggest in Pale where Mr Karadzic had his headquarters during the 1992-1995 war.
Mr Karadzic is in custody pending his transfer to the tribunal in The Hague.
An appeal is said to have been posted by his lawyer just before the Friday deadline in order to delay the process.
Any appeal is expected to fail and Mr Karadzic is likely to be sent to the Netherlands within days, correspondents say.
Supporters of Mr Karadzic, who faces charges of genocide and crimes against humanity, gathered in Belgrade and Pale, near Sarajevo, to hold protests and church vigils.
Many carried posters, flags, or posters of Mr Karadzic or lit candles. Others wore t-shirts with the phrase "Serbian Hero" underneath his image.
Mladen Bosic, president of the Serb Democratic Party founded by Mr Karadzic, joined the Pale demonstration.
Mr Bosic said he had visited the former Bosnian Serb leader in prison.
"I can tell you that I was surprised in how good shape and condition is Doctor Karadzic, he is mentally perfectly well, and actually he's spreading positive energy around him," he said.
He later visited Mr Karadzic's daughter.
Proof of postage
Mr Karadzic was arrested in Serbia last week after 11 years on the run. He had changed his appearance, having grown a long grey beard and ponytail and was working as an alternative therapist.
Under Serbian law, all Mr Karadzic, 63, needs is proof that his appeal was posted before the deadline and the court must simply wait for it to arrive.
Once the court receives the appeal notice from Mr Karadzic, a panel of judges will meet to consider it. If it fails, as it is expected to do, the case will be handed over to the government, which issues the final extradition order.
Mr Karadzic led the formation of a separate Bosnian Serb assembly in 1991 - one of the sparks that ignited the 1992-1995 Bosnian war.
He has been indicted for crimes against humanity and genocide over the massacre of up to 8,000 mainly-Muslim Bosniaks at Srebrenica in 1995.
He has also been charged over the shelling of Sarajevo, and the use of 284 UN peacekeepers as human shields in May and June 1995.