A magnitude 6.6 earthquake struck off Indonesia's Java island on Friday but there was no risk of tsunami, the country's geophysics agency said. The quake was strongly felt in Surabaya, Tuban, Denpasar, and Semarang, Abdul Muhari, spokesperson for Indonesia's Disaster Agency, said by phone. The European-Mediterranean Seismological Center (EMSC) put the magnitude at 6.5 with a depth of 592 km (368 miles). "There is no damage reported so far because the quake is very deep," Muhari said. "I don't think there will damages but we are still monitoring." Indonesia straddles the so-called "Pacific Ring of Fire", a highly active seismic zone, where different plates on the Earth's crust meet and create a large number of earthquakes and volcanoes.