Sixteen male migrants have been detained after three small boats landed on UK shores, authorities said.
The men, most of whom claimed to be Iranian, had medical checks after the perilous voyages before being taken for questioning by immigration officials on Sunday, the Home Office said.
Eight had been crammed into a small dinghy which was towed to Dover, Kent, by the Border Force at around 9.35 am on Sunday.
Their vessel had reportedly first been spotted by fishermen and the occupants were seen wrapped in blankets on Sky News footage.
Six men, who said they were either Iranian or Iraqi, were detained after earlier being spotted on a beach in Kingsdown, north east of Dover.
A further two men were detained after an abandoned dinghy was spotted on Warren Beach, in Folkestone, around 14 miles away.
The incident comes after a recent rise in the number of migrants attempting to cross the English Channel from France in small boats.
Home Secretary Sajid Javid cut short his Christmas break last month to deal with what he described as a “major incident” unfolding in waters off the south coast.
Mr Javid has promised to do more to tackle the issue, saying it is of “grave concern” that people are attempting the perilous crossing.
A coastguard spokeswoman said it had been assisting the Border Force on Sunday morning, adding: “HM Coastguard is committed to safeguarding life around the seas and coastal areas of this country.
“We are only concerned with preservation of life, rescuing those in trouble and bringing them safely back to shore, where they will be handed over to the relevant partner emergency services or authorities.”