TEHRAN, Iran (AP) — As Iranians take to the streets in the biggest demonstrations in nearly a decade, residents of the increasingly tense capital say they sympathize with the protesters' economic grievances and anger at official corruption.

The Associated Press spoke to Iranians in Tehran on Tuesday, the sixth day of protests that have seen at least 21 people killed and hundreds arrested across the country. The protests, which have erupted in several cities, are the largest since those that followed the disputed 2009 presidential election.

Residents cast nervous looks at the growing street pre...