An earth­quake with a pre­lim­i­nary mag­ni­tude of 6.2 shook Is­tan­bul and oth­er ar­eas Wednes­day, prompt­ing wide­spread pan­ic and scores of in­juries in the Turk­ish city of 16 mil­lion peo­ple, though there were no im­me­di­ate re­ports of se­ri­ous dam­age.

More than 150 peo­ple were hos­pi­tal­ized with in­juries sus­tained while try­ing to jump from build­ings, said the gov­er­nor’s of­fice in Is­tan­bul, where res­i­dents are on ten­ter­hooks be­cause the city is con­sid­ered at high risk for a ma­jor quake.

The earth­quake had a shal­low depth of 10 kilo­me­tres (about 6 miles), ac­cord­ing to the Unit­ed States Ge­o­log­i­cal Sur­vey, with its epi­cen­tre about 40 kilo­me­tres (25 miles) south­west of Is­tan­bul, in the Sea of Mar­mara.