NEW YORK (AP) -- An ``al-Qaida sympathizer'' who plotted to bomb police and post offices in New York City as well as U.S. troops returning home has been arrested on numerous terrorism-related charges, city officials said Sunday.

Mayor Michael Bloomberg announced at a news conference the Saturday arrest of Jose Pimentel of Manhattan, ``a 27-year-old al-Qaida sympathizer'' who the mayor said was motivated by terrorist propaganda and resentment of U.S. troops in Afghanistan and Iraq.

The mayor said Pimentel, a U.S. citizen originally from the Dominican Republic, was ``plotting to bomb police patrol cars and also postal facilities as well as targeted members of our armed services returning from abroad.''

Authorities have no evidence that Pimentel was working with anyone else, the mayor added.

``He appears to be a total lone wolf,'' the mayor said. ``He was not part of a larger conspiracy emanating from abroad.''

Instead, Bloomberg said, Pimentel represents the type of threat FBI Director Robert Mueller has warned about as U.S. forces erode the ability of terrorists to carry out large scale attacks.

Pimentel, also known as Muhammad Yusuf, is accused of having an explosive substance Saturday when he was arrested that he planned to use against others and property to terrorize the public.

The charges accuse him of conspiracy going back at least to October 2010, and include first-degree criminal possession of a weapon as a crime of terrorism, and soliciting support for a terrorist act. He was to be arraigned later Sunday.

``This is just another example of New York City because we are an iconic city ... this is a city that people would want to take away our freedoms gravitate to and focus on,'' Bloomberg said.

Police Commissioner Raymond Kelly said a confidential informant had numerous conversations with Pimentel on Sept. 7 in which he expressed interest in building small bombs and targeting banks, government and police buildings.

Pimentel also posted on his website trueislam1.com and on blogs his support of al-Qaida and belief in jihad, and promoted an online magazine article that described in detail how to make a bomb, Kelly said.

Among his Internet postings, the commissioner said, was an article that states: ``People have to understand that America and its allies are all legitimate targets in warfare.''

The New York Police Department's Intelligence Division was involved in the arrest. Kelly said Pimentel spent most of his years in Manhattan and lived about five years in Schenectady.

Asked why federal authorities were not involved in the case, Manhattan District Attorney Cyrus R. Vance Jr. said there was communication with them but his office felt that given the timeline ``it was appropriate to proceed under state charges.''