The state fire marshal's office is investigating the explosions of three pipe bombs last night in Hampstead, Carroll County.
Deputy Fire Marshal Robert Thomas said the devices were placed in a cable television junction box and two mail boxes. No one was injured.
The first bomb went off about 10 p.m. in the junction box belonging to Prestige Cable TV in the first block of Fairmount Road.
A company spokeswoman said today about 400 customers lost service. She could not estimate when service would be restored.
Later, two mailboxes in the 4300 block of Gross Mill Road were destroyed by pipe bombs.
Mr. Thomas said the devices were about 6 inches in length and 1 1/2 inches in diameter. He said some fragments were recovered and will be examined by explosives experts.
There was no apparent motive for the incidents, he said.