ATHENS, Oct. 21 (Xinhuanet) -- A strong earthquake measuring 6.0 onthe Richter scale rocked the islands of Samos and Chios in the eastern Aegean Sea in the first hours of Friday.

    There are no damage reported at present.

    The earthquake, which struck at 00:40 a.m. (local time), has the same epicenter in the Aegean Sea near the opposite Turkish coast, about 430 kilometers southeast of Thessalonik as the twin 6.0 and 5.9 Richter tremblers that jolted the same region on Monday.

    Seismologists were on alert after Friday's quake, which was followed by intense post-seismic activity, with the strongest aftershock recorded just four minutes after the main quake, with amagnitude of 5.3 Richter.

    Friday's quake could be felt in the Aegean islands as far as Atttica prefecture.

    Two strong earthquakes measuring 6.0 and 5.9 on the Richter scale jolted the Aegean islands on Monday morning within a space of four hours, causing no damage.

    Several smaller tremblers have also been recorded in the area over the last 48 hours.

    According to authorities on Samos, the new strong quake caused concern among the local residents. They also said the quake had been longer in duration than any of the smaller tremblers over thepast two days.

    Seismologists were on alert after the new quake on Friday, which they said was followed by intense post-seismic activity, with the strongest aftershock, which registered 5.3 Richter, having been recorded just four minutes after the initial earthquake.

    Seismologists were concerned over what the called the "three sixes" (Monday's 6.0 and 5.9 Richter and Friday's 6.0 Richter quakes) recorded in the same region in the last few days.

    Similar statements were made by seismologist Gerassimos Houliaras, who said that aftershocks of 3, 4 or even 5 Richter should be anticipated. Enditem ¡¡