ATHENS, Greece (AP) — Greek geological experts say two new aftershocks have hit the western Greek island of Zakynthos, but no damage has been reported.

The Athens Institute of Geodynamics reports that the tremors occurred within seven minutes of each other. It says the first, a 4.4 magnitude quake, struck at 5:11 a.m. (0311 GMT). The epicenter was 78 kilometers (48 miles) south of Zakynthos and the depth was 10 kilometers (6.2 miles).

Seven minutes later, a 5.0 magnitude tremor hit 59 kilometers (37 miles) southwest of the island at a depth of 7 kilometers (4.3 miles).

Zakynthos was hit by a magnitude 6.4 earthquake on Oct. 26. Since then, there have been 21 aftershocks of at least 4.0 magnitude, with the strongest being magnitude 5.5.