MANILA/JAKARTA (AFP) - A strong 6.0-magnitude earthquake and a burst of volcanic ash struck a region south of the Philippine capital on Saturday in quick succession, but government experts said the events were unrelated. An earthquake hit the Bicol region early Saturday, shaking people from their sleep but causing no serious damage, the government said. The quake, with an epicentre off the coast of Burias island, about 275km southeast of Manila, occurred at 12:41 am (1641 GMT Friday), the government seismology office said. Just hours later, Bulusan volcano, located 250km southeast of Manila, ejected a column of ash about 600 metres into the air, which showered down onto several towns in Bicol, the government said. Government vulcanologists have raised the alert level for Bulusan from zero to level 1, indicating abnormal activity, possibly a sign of more ash eruptions to come. Meanwhile, airlines cancelled at least 36 flights to and from Jakarta on Saturday, affecting international carriers from Europe to Asia, because of ash from the Mount Merapi volcano, an airport spokesman said. In echoes of the disruption when thousands of flights were cancelled earlier this year after ash spewed from a volcano in Iceland, several major international carriers were hit in their Indonesian operations. Thirty-six flights to and from Jakarta from 11 airlines have been cancelled today. I think its for safety reasons due to the volcanic ash from Merapi, said Sudaryanto, a spokesman for Soekarno-Hatta International Airport. He listed the airlines that cancelled their flights as Singapore Airlines, Air Asia, Emirates, Malaysia Airlines, JAL, Turkish Airlines, Lufthansa, China Airlines, Korean Air, Tiger Air and the local airline Mandala. Separately, Cathay Pacific said on its website that flights to and from the Indonesian capital had been delayed and would depart on Sunday, if conditions improve. Mount Merapi, on Central Java, first started erupting on October 26, a day after a tsunami killed more than 400 people in a remote area off Sumatra island. The volcano, which is 430km from Jakarta, has so far killed 128 people, but this is the first time international flights have been affected. Singapore Airlines said that flights to and from the capital were temporarily suspended while Malaysia Airlines said flights were cancelled at least until Sunday. We will continue monitoring the situation, it depends whether the ash clouds still surround the region of Jakarta, a Malaysia Airlines spokeswoman told AFP. Flights to cities closer to Merapi - including Yogyakarta, Solo and Bandung - have also been affected. Ash, deadly heat clouds and molten debris gushed from the mouth of Mount Merapi and shot high into the sky Friday, triggering chaos on the roads as people fled their homes. The death toll from Fridays eruption - its most violent in more than a century - stood at 85, with scores more suffering severe burns. Many of the dead were from Argomulyo village, 18 kilometres from the crater, according to emergency response officials and witnesses, with several children under the age of 10 killed.