NEW YORK - Ahmad Khan Rahami, the Afghan-born man arrested for this weekend’s series of bombings in New York and New Jersey, had travelled to Pakistan and Afghanistan several times without detection by the US government, according to media reports citing officials.

Rahami’s travels and time spent in Pakistan are the subject of intense scrutiny by US investigators who are now trying to determine whether the suspect became radicalised during his travel and what connections, if any, he may have had to foreign terrorist organisations or militants, The Daily Beast said.

Rahami has made at least three and possibly four trips to Pakistan over the past 10 years, one official said. It’s not clear where he travelled within the country and particularly if he spent time in areas near the border with Afghanistan that have been the frequent target of US drone strikes.

Rahami’s father also was in Pakistan as recently as July 2011, according to the family’s Attorney, who informed a judge in a civil suit to which the elder Rahami was a plaintiff that he was not expected back in the country in time for a court proceeding the following month.

In September 2011, the lawyer informed the judge that while the father had returned, his “family is in Afghanistan” but was expected to return within days.

A senior US official was quoted as saying that Rahami’s oldest brother is in Pakistan now.

Two US officials told The Daily Beast that Rahami was not on any US government terrorist watch lists. Had he been, it’s possible that Federal authorities would have been alerted if Rahami travelled outside the United States.

US Congressman Albio Sires told the Bergen Record that Rahami contacted his office via email in 2014 seeking an immigrant visa for his wife in Pakistan who was 35 weeks pregnant and whose Pakistani passport had expired.

Rahami came to the US as a child in 1995 as the son of an Afghan asylum seeker. There has been some confusion over when Rahami or his family were officially granted legal residency in the country, but it may have taken some time for their application to be processed and approved.

Rahimi had a series of escalating run-ins with the law beginning in 2008, when he spent a day in jail for unpaid parking tickets, and another in 2012 after he allegedly violated a restraining order, The New York Times reports.

In 2014, Rahami spent three days in jail on weapons and aggravated assault charges, after allegedly stabbing a person in the leg, The New York Times reports. A grand jury dropped Rahami’s charges for the fight, which allegedly began as a domestic dispute.

The hunt for a New York-area bomber began Saturday morning when a set of pipe bombs exploded at a 5K race in New Jersey. The search escalated following a large explosion that injured 29 people in Manhattan’s Chelsea neighborhood Saturday night.

The 28-year-old was found sleeping in the doorway of a bar in Linden, New Jersey, by a police officer late Monday morning. When he was awakened, Rahami allegedly shot the officer, who returned fire. The arrest came hours after police and the Federal Bureau of Investigation raided Rahami’s family residence in the neighbouring city of Elizabeth.

A law-enforcement official said that a fingerprint taken from a second unexploded device on West 27th Street in New York City identified Rahami as the suspect and was corroborated by surveillance footage taken there and at West 23rd Street, where the first bomb exploded.

No other suspects or persons of interest have been named so far.

Authorities at a Monday Press conference said they have no reason to believe there is a terrorist cell.

A New Jersey neighbour of the family told The New York Times that one of Ahmad Rahami’s brothers went to Afghanistan following a fight with a police officer. A civil discrimination suit filed by the Rahami family against the city of Elizabeth in 2011 cites Muhammad K. Rahami’s arrest.

The Rahami brothers’ father claimed in the lawsuit that City officials harassed him at his business, First American Fried Chicken, with unnecessary citations and summonses. The court documents state that City officials forced the restaurant to close at 10 p.m. every night, while similar neighbourhood restaurants were allowed to stay open later. The lawsuit also claimed the family was the target of anti-Muslim sentiment from neighbours and officials, including one neighbour who allegedly complained to police that “Muslims make too much trouble in this country” and that “Muslims should not have businesses here.”