CALAIS, France (AP) — Lines of migrants with their lives in small bags walked to a registration center in the French port city of Calais Monday, the first day of the mass evacuation and destruction of the filthy camp they called home.

French authorities are beginning a complex, major operation to shut down the makeshift camp, uprooting thousands who made treacherous journeys to escape wars, dictators or grinding poverty and dreamed of making a life in Britain.

Under the eye of more than 1,200 police, the first of hundreds of buses arrived to begin transferring migrants to reception centers around France where they can apply for asylum. The camp will then be leveled in a weeklong operation. Hotels and even castles are among the hundreds of centers officials have been converting to migrant housing.

Authorities say the camp, known as the jungle, holds nearly 6,500 migrants who are seeking to get to Britain. Aid groups say there are more than 8,300.

The harsh reality of the move hit migrants on Monday. Some were happy to leave, others were confused or in shock.

Afghan Imran Khan, 35, risks expulsion if he accepts the French plan to move him to a reception center, because his fingerprints were taken in another European country. Under European rules, he must be sent back to the country where he first registered. "I will decide tomorrow (what to do)," he said.

Khan lives in a filthy tent, one of hundreds that are expected to be destroyed by the end of the week as their occupants depart, gradually closing down the camp that sprang up behind an official shelter housing women and providing showers and daily meals.

Unaccompanied minors, many with family members in Britain, were to be housed on-site in containers set up earlier this year as their files are studied in London to see if they qualify for a transfer across the English Channel. The humanitarian organization France Terre d'Asile says 1,291 unaccompanied minors live in the camp.

One 16-year-old Eritrean, Daniel, was heading to the registration center with his cousin, also an unaccompanied minor. "I'm not happy because it's finished, the jungle. I want to go to the U.K.," he said.

In Calais for eight months, he said he has tried daily to jump on trucks heading across the English Channel to Britain, like other migrants in the camp. "I don't want France," he insisted.

Fourteen migrants have died this year in the Calais area.

The unofficial camp, which sprang up 18 months ago, was previously tolerated but given almost no state help. Aid groups, and hundreds of British volunteers, have provided basic necessities. It devolved into a slum town where tensions bubbled, friendships formed and smugglers thrived.