A strong offshore earthquake of magnitude 6.5 shook several towns in western Colombia on Tuesday, but no damage or injuries were reported, the country's Geological Service said. No tsunami warning was issued. The quake struck at 10:43 a.m. local time (11:43 a.m. EDT/1543 GMT) at a depth of 21 km (13 miles) and nearly 100 km west of Colombia's Pacific coast.