During the second accident, which occurred Monday at dawn 3.7 nautical miles from the coast of Samos, the migrants' boat capsized and six people, five men and a woman, were rescued lifeless.
Twelve migrants, including an infant, died Monday October 19 during two accidents in the Aegean Sea, according to the coast guard.
A coast guard official said a fast migrant boat collided with the left flank of the port police patrol.
Fatal accidents of migrant boats trying to cross into Europe via the Greek islands located near the western Turkish coast are frequent.
In September, one person died and 25 others disappeared when a migrant boat sank off the Greek island of Gavdos, near Crete.