The reaction of Chinese social media users to a spate of recent violent attacks has exposed widespread discontent about the nation¡¯s downturn, as economic pressures mount.

Shanghai police reported a stabbing Wednesday morning in one of the city¡¯s metro stations, which ¡ª like other subway lines in major Chinese cities ¡ª has security checks at its entrances. The suspect was detained after injuring three people and the case is under investigation, police said in a statement.

In a country where violence is relatively rare, the incident became a top trending item on social media platform Weibo, garnering some 164 million reads with users speculating on the attacker¡¯s motive. Some suggested the culprit was a stocks investor, a group battered during China¡¯s $7 trillion market meltdown earlier this year.