A statement Friday said the eight were detained in three cities with help from the European Union police agency Europol and law enforcement agencies in Hungary, Croatia, Slovenia and Italy. Kosovo police allege the gang smuggled 35 ethnic Albanian minors mostly to Italy. The statement says smugglers were paid 3,000-3,500 Euros ($3,370-3,930) per person.
In recent years, Kosovo has been among the main countries of origin for migrants to western European countries, especially Germany.
Spanish police say more than 100 people have been arrested in a pan-European operation against a criminal organization suspected of trying to smuggle some 6,000 Ukrainians into Britain and Ireland.
A statement Friday said 56 Ukrainians with false identity documents were among those arrested at more than a dozen Spanish airports. Police could not say when the arrests took place.
Police in France, Belgium, Ukraine and Poland also arrested some 50 people, including several alleged gang leaders.
Spanish police arrested one leader in March in Barcelona and seized more than 100 ID cards and Polish passports.
European Union police agency Europol, which helped coordinate the operations, says migrants were offered complete packages, including ID documents, plane tickets and accommodation. They entered Poland first and then traveled on to other countries.
More than 100 migrants have staged a protest in Serbia to demand access to European Union countries that have closed their doors to them.
The demonstrators gathered Friday in a Belgrade park carrying banners reading, "Open Borders" and "No More War."
Thousands of migrants have been stuck in Serbia for months after the Balkan country's EU neighbors beefed up border controls to keep migrants out.
While most migrants in Serbia are staying in asylum centers, hundreds of men have been camping in parks or abandoned warehouses in Belgrade seeking ways to cross illegally into Hungary or Croatia.
Serbian authorities recently instructed aid groups to stop delivering food outside migrant centers in hopes of getting the men off the streets.
Lithuanian officials say 35 Syrian refugees, relocated in the Baltic nation under a European Union plan to distribute 160,000 refugees across the bloc, have left in search of a better life elsewhere in Europe.
Robertas Mikulenas, head of Rukla refugee reception center in Lithuania, says a group of 16 adults and 19 children left Monday, likely for Germany.
Mikulenas said Friday they are "free to leave," adding they could lose benefits in Lithuania if they do not come back within a month.
Syrian Mohammed Ali Abdula earlier told the LNK channel they thought Lithuania was "like Germany and Sweden" but after discovering that wasn't the case, "it became obvious we do not want to stay."
Abdula cited "the size of relief and integration process" for his family's departure.