BIHAC, Bosnia-Herzegovina (AP) — The Latest on immigration to Europe (all times local):

2:15 p.m.

The European Union law enforcement agency says police across the continent have concluded a two-year investigation into a “massive” criminal network that was using trucks to smuggle migrants into western Europe.

Europol said Thursday that police in Romania detained four suspected members of the gang, which smuggled nearly 580 people from outside Europe through the Romanian city of Timisoara and then westward.

Numerous migrants have lost their lives in recent years after being crammed into tractor-trailers, without sufficient air or water, for the journey across Europe.

Europol said the investigation was launched by German police last year and also involved authorities in Austria, Greece, Czech Republic, Hungary and Britain.

It said the gang was composed of at least 36 people who earned more than 2 million euros ($2.2 million).

2 p.m.

Authorities in northwestern Bosnia are threatening a curfew in two large local migrant camps to press the central government to relocate people to other parts of the country.

The local government in the region bordering Croatia says a “full blockade” of the badly congested Bira and Miral camps will start Friday and continue until the situation is resolved.

The camps, hosting some 2,000 people, near the towns of Bihac and Velika Kladusa are run by the International Organization for Migration.

That part of Bosnia has been swamped with thousands of migrants hoping to illegally cross into neighboring European Union member Croatia.

Local authorities say that from Friday no more people will be allowed into the camps, while only those heading towards the Croatian border will be allowed to leave.