The Federal Bureau of Investigation (FBI) has opened an investigation into the killing of three young Muslims at a US college town in North Carolina, US President Barack Obama said yesterday after allegations arose that the shooting was a hate crime.

In addition to the local investigation, Obama said, the FBI would also examine whether federal laws were violated when the suspect, Craig Stephen Hicks, allegedly gunned down dentistry student Shaddy Barakat, his wife Yusor Mohammad and her sister, Razan Mohammad Abu-Salha.

The attack on Tuesday near the campus of the University of North Carolina in Chapel Hill has attracted international coverage, with the three victims all practising Muslims.

"No one in the United States of America should ever be targeted because of who they are, what they look like or how they worship," Obama said in a statement.

The victims were all active in raising money for Syrian refugees in Turkey.

After a preliminary investigation, local police said that the shooting followed a dispute over parking spaces between Hicks and the couple, who were his neighbours.

Hicks' wife, Karen Hicks, told a press conference earlier this week that her husband believed in the equality of everyone and the shooting was not connected to religion.

- dpa