Federal officials and city police have been investigating a social media post by someone claiming to be the "NY bomber," responsible for the explosion in Manhattan that injured 29 people. But federal and city sources have reportedly already determined that the post is not linked to the individual or individuals responsible for the bombing.

Two messages were posted on Tumbr Sunday after the Saturday night (17 September) blast of a pressure-cooker device rigged to explode when triggered by a smart phone signal, damaging buildings in the Chelsea neighborhood. (A second suspected device found nearby failed to detonate).

Tumblr removed the entries within an hour of the first media report on the message.

The writer promised more bombs in a copy of the post obtained by WPIX-TV, declaring: "This is not the end, this is just the beginning. I will be remembered. I will make a difference. I will eliminate my targets before it is too late."

But federal and local officials now say they don't believe the post is related to the explosion, and that the message has been linked to a person in North Carolina, reports WPIX.

Meanwhile, officials are also probing if an explosive device rigged to go off in New Jersey is linked to the one in Manhattan, ABC News reports.

The New Jersey blast in a garbage bin took place in Seaside Park the same day as the Chelsea blast along the route of a planned 5k charity race to benefit US Marines and sailors. No one was injured, but the race was cancelled.

The device in New Jersey — three pipe bombs wired together— and the one that caused the blast in New York City were both set off with cell phone signals, according to two law enforcement sources. They cautioned, however, that the probe is only in its preliminary stages.

The Tumblr poster riveted online news. The individual claimed to have set the bomb in a protest over the oppression and discrimination against the LGBTQ community, blacks and the underprivileged — though many members of the LGBTQ community live in Chelsea, one of the city's most LGBTQ-friendly neighborhoods.

The post is entitled: "I'm the NY bomber. This will be my manifesto."

The first entry began: "I don't know exactly how I feel about taking human lives. However, what I do know is that If I don't do what needs to be done nobody will pay attention," the post wrote. "LGBTQ+ people are much more likely to commit suicide than straight cisgendered people. It seems that nobody cares ..."

A second entry stated: "Manufacturing test explosives. Hi. You probably have all seen the news by now, the explosives detonated in New York City, that was me. Those were just some tests, I know where I have made errors and I will not make the same mistake next time.

"I did it because I cannot stand society. I cannot live in a world where homosexuals like myself as well as the rest of the LGBTQ+ community are looked down upon by society.

"I am not going to stand by while there is inequality in my country such as the racism being seen in white police officers all over the country. I am not going to live in a country where it is OK to have a misogynist, xenophobic, racist Islamophobic, republican candidate running for President of The United States!"

The entries were marked with the rainbow flag of the LGBTQ movement.

New York Governor Andrew Cuomo has called the blast "terrorism," but also clarified that it is not likely "international terrorism."

The online alt-right movement seized on the Tumblr post to attack the "crazed leftist" behind the bombing. The Daily Beast indicated the message could have been faked by a member of the alt-right to single out their favorite kind of "villains."

A Tumblr spokesperson said in a statement that the blog "was terminated as it violated Tumblr's terms of service and community guidelines.

"In addition, we have been contacted by law enforcement regarding their investigation, and are responding to their requests consistent with our policies."