>> Police in Austin, Texas on Tuesday said the three package bombs that have killed two people and severely injured two others were constructed with skill and sophistication and appear to be related. Reuters correspondent, Jon Herskovitz is in Austin.>> The Austin Police Chief Brian Manley said that these were sophisticated bombs, they were powerful bombs.
They've been looking very closely at the bombs and trying to get as much as possible from the construction that would help them find the suspect or suspects who placed these bombs which caused two people to be killed so far this month in Austin.>> They are not coming through the mail.
>> The package bombs were left in front of homes in three separate neighborhoods within the last two weeks. The first on March 2nd, killed a 39-year-old man on the doorstep of his home, northeast of downtown. The second was delivered to a home in East Austin and was brought into the kitchen where it exploded, killing a 17-year-old boy and injuring his mother.
Police say she is expected to survive. The third detonated about four miles away in Southeastern Austin, seriously injuring a 75-year-old woman. She is in critical condition. The victims of the first two bombs are black, the injured elderly woman is Hispanic, raising the possibility the attacks were hate crimes.
>> We are just not going to ignore the fact that the three victims that were targeted specifically that we know of were all people of color.>> Police have received more then 250 calls about suspicious packages as of Tuesday afternoon. None resulted in the discovery of a bomb, but Chief Manley urged residents to remain vigilant.
>> If you see something, say something, call us.>> People are fearful, they're telling their children, don't pick up packages, don't take packages in. And the randomness is really frightening people, especially those who live nearby. And for people of a certain age the word Unabomber is coming up in conversations.
>> Monday's attacks occurred as hundreds of thousands of visitors poured into Austin for South by Southwest. Police said they do not believe there's any connection between the bombings and the festival.