After a day-long standoff and suspected hostage situation at a Clayton County house, police discovered no one was inside.

Clayton police surrounded the house all day Wednesday, sealing off the neighborhood and leaving other residents stranded outside their own homes.

Police said they believed Albert Williams was armed and with another woman in the house. They used a cellphone during the standoff to maintain contact with Williams, who allegedly told authorities he was in the residence on the 5900 block of Saddlecreek Circle.

However, when SWAT members threw a "flash" grenade into the house and stormed it Wednesday evening, Williams and the female were nowhere to be found.

"He was probably never in there," said Charlene Watson-Fraser, a Clayton County police spokeswoman.

The situation began when police received a call just after 9 a.m. from Williams' brother-in-law, who discovered the suspect inside the house. Williams refused to come outside and told his brother-in-law he had something inside for him, Watson-Fraser said.

Police said they did not know how Williams knew the woman or the level of danger she was in. Watson-Fraser said the woman acted as a liaison between Williams and police and sounded nervous on the phone.

Williams, who has a history of domestic abuse, is wanted by police for damaging government property and theft, police said.

Police are continuing to investigate.