A St. Paul police officer issued an apology Tuesday for dressing in a hijab for Halloween and posing for a picture that exploded on the Internet among the Twin Cities' Somali and Muslim communities.

"I apologize to anyone who may have been offended by the recently publicized photo which showed me at a private Halloween party on my personal time," officer Robert Buth said. "I sincerely regret that the image, which was never intended to become public, may have been viewed to be insensitive to the Muslim community."

The picture was posted on Twitter about 10 weeks ago, and resurfaced Sunday. Somali and Muslim community members began discussing the image online and brought it to the attention of the department's Twitter account.

Police Chief Thomas Smith opened an investigation Monday and issued a statement saying that he expected all officers to respect diversity.

On Tuesday, Smith said that he respected Buth's efforts to apologize. "I believe his apology is sincere and that he will work to correct any negative perceptions brought about by the image," Smith wrote.

"In his 13-year career with the St. Paul Police Department, Officer Buth has been recognized by our communities for his service. We expect that he will once again draw upon those experiences as he works to rebuild their trust."

In the picture, Buth is wearing a red jilbaab, an especially concealing type of hijab, has a cellphone tucked between his face and the garment and sports a Target name tag with a very common Somali name.

Target Corp. spokeswoman Molly Snyder has said that the officer has provided off-duty security at a local Target store.

On Tuesday, Somali and Muslim community activists said the apology was a good first step but that more needed to be done. "It helps to move forward," said Lori Saroya, executive director of the Minnesota chapter of the Council on American-Islamic Relations. She suggested that the St. Paul police give the officer diversity training.

Activist Ilhan Omar said that even as a Halloween costume, Buth's outfit was inappropriate. "I think a broader message needs to be sent out that it is understood that something like that is unacceptable," she said. Omar said a community dialogue involving St. Paul police and members of the Somali community is also needed.

Police spokesman Howie Padilla said that the internal affairs investigation into the photo is ongoing and that Buth remains assigned to the department's K-9 unit.

Staff writer Nicole Norfleet contributed to this report. Chao Xiong • 612-270-4708 Twitter: @ChaoStrib