(CNN) A child has died after a boat carrying migrants capsized off the Greek island of Lesbos, in what is believed to be the first reported death since Turkey announced it was opening its borders with Europe last week.

The makeshift boat was carrying 48 people, accompanied by the Turkish coastguard, when it entered Greek waters early Monday, Greece's coastguard said in a statement.

The passengers "overturned the boat" as it was approached by the coast guard, according to Greek officials, who added this was a "common tactic" used by traffickers to force a rescue.

Of the passengers, 46 were "recovered unharmed" and two unconscious children were taken to hospital in Lesbos, the coast guard said. One of these children later died.

The death comes as the number of refugees traveling to Greece's Aegean islands has surged in the last several days, sparking concerns about living conditions in already grossly overcrowded camps and prompting blockades from frustrated local residents, aid workers on the ground told CNN.

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