STAMFORD - Stamford police closed off Rock Spring Road Sunday morning following a standoff with a man who locked himself inside an attic.

Police say they were notified of a break-in at a home on Rock Spring Road about 10:15 a.m. They say the caller identified the man who allegedly broke into the house as a former roommate.

After a 90-minute standoff, police say the suspect surrendered. The city's bomb squad was then called in and found bomb-making materials inside the house, police say. The materials were detonated.

Police aren't releasing the name of the suspect. They say he hasn't yet been charged.

The investigation is expected to go on for hours, police say.