Bulgaria's economy returned to growth in the third quarter despite ongoing political tensions in the EU's poorest country, official preliminary data showed on Thursday.

Helped by a modest recovery in the eurozone that has boosted other central and eastern European emerging economies, gross domestic product (GDP) grew 0.6 percent after shrinking 0.1 percent in the last quarter.

Five people were arrested in clashes on Tuesday between police and Bulgarian students who had cordoned off parliament in the capital Sofia as part of an anti-government protest, police said.

Skirmishes erupted and at least one person was injured as officers tried to push back the students, who had formed a tight human chain along the metal fence encircling the building and vowed to prevent lawmakers from leaving.

Bulgaria has turned back more than 100 clandestine immigrants at its border with Turkey at the weekend, an interior ministry official said Sunday, amid rising nationalist tensions in the European Union's poorest member.

The group of migrants was stopped in the Strandzha mountains in the southeast of the country, the ministry's secretary general Svetlozar Lazarov told public radio.

Bulgaria's interior minister announced Monday an action plan aimed at speeding up expulsions of economic migrants, as the EU's poorest country grapples with a sharp rise in refugees.

Tsvetlin Yovchev said that migrants "who have no grounds to request humanitarian or refugee status" would be expelled from Bulgaria within three days.

Some 2,000 Bulgarian students rallied in Sofia on Friday for a traditional march that quickly morphed into a demand for the ouster of their country's beleaguered Socialist-backed government.

The demonstration, springing forth from a gathering commemorating 18th and 19th century intellectuals and revolutionaries, took place against a backdrop of protests and occupations in universities around the country.

The siblings of Maria, the little blonde girl found in a Greek Roma camp this month, will be placed in homes until their parents can care for them, Bulgarian social services said Thursday.

The agency said it will find emergency housing for the children -- aged two to 15 -- "with relatives, in foster homes and specialized institutions."

Bulgaria said Tuesday it will ask the Greek authorities to hand over a young girl found in a Roma camp this month, who was wrongly thought to have been abducted.

"The state child protection agency will undertake the necessary actions for the return of Maria... who was indisputably proven to be the child of Sasha Ruseva and Atanas Rusev from the town of Nikolaevo," the agency said in a statement.

The Bulgarian Roma family of Maria, wrongly thought to be an abducted western European child when she was found in Greece last week, wants her back but fears social services will keep her.

"Give us Maria! We will take her home and share our bread with her," her eldest sister Katia Ruseva said Saturday in the central Bulgarian town of Gurkovo, where she lives with her husband and two children.

A small group of Bulgarian students occupied the largest university in Sofia Saturday, demanding the resignation of the Socialist-backed government and an end to corruption in politics.

Around 70 students hunkered down inside the university's main building in downtown Sofia, blocking entrances and hanging banners inscribed with the word "Occupation" from windows.

DNA tests confirmed Friday a Bulgarian Roma couple living in dire poverty as the biological parents of Maria, a mystery blond girl discovered last week in a Greek Roma camp.

"DNA samples showed that Sasha Ruseva is the biological mother and Atanas Rusev is the biological father of the child called Maria," Bulgaria's interior ministry chief of staff Svetlozar Lazarov told reporters.