Greece has increased security on the island of Kos which is struggling to cope with an influx of migrants.
Greek Minister of State Alekos Flabouraris said a ship with a capacity for at least 2,500 people would be dispatched to the holiday island.
The cruise liner would be converted into a reception centre to process arrivals and would dock in the main port of the island, he said.
Two riot police units were dispatched to Kos from Athens and police reinforcements from nearby islands were also drafted in, police sources said.
Yesterday, skirmishes erupted at a makeshift reception centre at a sports stadium during which police used fire extinguishing spray to disperse people.
Hundreds of people, including infants, are still inside the stadium in scorching temperatures, waiting for papers that would allow them to travel.
Witnesses said those waiting had no food and little water.
Scuffles broke out outside one of two closed gates of the compound between a small group attempting entry and riot police.
Police threw a tear gas canister to disperse the group of about 40 people and also violently pushed migrants to keep them in a tightly packed queue outside a processing office.
Mr Flabourasis said the Greek government was going to do as much as possible to ease the problems facing Kos due to the migrant crisis.
Greece, which mired in its worst economic crisis in decades, has found itself in the spotlight in recent months as Europe grapples with a stream of migrants fleeing war and poverty.
Tens of thousands have crossed into Greece from Turkey along its long island coastline.
Dozens of tents lined a beachfront promenade leading from Kos's main port today.
There have been reports of harassment by private security personnel, medical charity Medicins Sans Frontieres (MSF) said.
"The Kos authorities have clearly stated that they have no intention of improving the situation for these people as they believe that this would constitute a 'pull factor,'" said Bricede le Vingne, MSF head of operations.
"But the truth is that people fleeing war will keep oncoming whether or not the authorities are trying to stop them from doing so."
A coastguard spokeswoman said more than 200 migrants had been rescued in the past 24 hours on the island. Most arrivals are undocumented.
The United Nations refugee agency UNHCR said 124,000 had landed on Greek islands this year.
Last week it called conditions for migrants on Kos and other islands "shameful", and said about 3,000 migrants and refugees were waiting to be registered by police.
Greece and its international lenders reached a multi-billion euro bailout agreement yesterday after months of acrimonious negotiations.
