A suicide bomber on Wednesday hit a police station in northern Baghdad, leaving at least 4 people killed and 13 others wounded, an Interior Ministry source said, Xinhua reported.
"Now we found 4 killed and 13 wounded, the death toll may continue to rise," the source told Xinhua on condition of anonymity.
At least three explosions were heard rocking Baghdad city early morning on Wednesday, according to Xinhua reporters, but no reports of the other two's casualties.
Violence and sporadic high-profile attacks are still common in Iraqi cities as part of recent deterioration in security which shaped a setback to the efforts of the Iraqi government to restore normalcy in the country about five months after violence-torn Iraq held parliamentary elections on March 7.
U.S. forces have pulled out of Iraqi cities and are working to formally end combat operations by Sept. 1, cutting the U.S. military force from just under 90,000 to 50,000. However, some local analysts still worry about whether the Iraqi forces are ready to replace the American soldiers amid continued insurgent attacks.