Five Turkish warships taking part in the Beyaz Firtina 2014 naval exercise entered Greek territorial waters in the Aegean Sea on Monday.
In a statement, Greeces National Defense General Staff (GEETHA) said the Kemal Reis, Meltem, Imbat, Ruzgar and Firtina vessels did not stay within the annual drills delineated area and were observed sailing around the Cyclades island complex.
Greek coast guard officers arrested 16 immigrants off the eastern Aegean island of Chios on Monday for trying to enter the country illegally.
Authorities have also detained one person on charges of human smuggling.
The immigrants were reportedly taken to the islands Skylitseio Hospital for medical tests.
The nationalities of those arrested was not made known.
A 17-year-old boy died on Monday after stepping onto an electrified rail on the ISAP electric railway near Irini station in northern Athens.
According to reports, the teenager and two friends were attempting to cross the tracks with the intention of spraying graffiti when the 17-year-old lost his balance and stepped onto the live rail.
Police on Monday were investigating two separate arson attacks in which a total of eight cars were damaged.
The first attack occurred in the parking lot of an OTE telecom branch in Halandri, northern Athens, at 9 p.m. on Sunday.
At 2.45 a.m. on Monday, two more cars were torched at an auto dealership in Kifissia, north of Halandri.
An unidentified man was killed in the early hours on Monday while trying to cross Syngrou Avenue, south of central Athens, after crashing his vehicle into a protective barrier.
Investigators believe he was trying to reach help after sustaining injuries in the crash when he was hit by an oncoming vehicle on the high-speed avenue.
PASOK leader Evangelos Venizelos has labelled unconstitutional a request by SYRIZA chief Alexis Tsipras for early general elections.
Venizelos held a news conference shortly after Tsipras met with President Karolos Papoulias, where he suggested that the government lacked the legitimacy to continue. Tsipras called for national elections as soon as possible.