Investigators were searching on Tuesday for clues to the motive behind the bombings and attempted bombings in New York and New Jersey over the weekend and to determine whether the Afghanistan-born suspect had accomplices or was radicalized overseas.

Ahmad Khan Rahami, 28, was arrested on Monday in Linden, New Jersey following a dramatic gun battle with police after they were summoned by a neighborhood bar owner who thought the bearded man sleeping against his closed tavern’s front door in the pouring rain resembled the bombing suspect.

Rahami and two police officers were wounded in the exchange of gunfire.

Authorities did not offer any immediate information on the possible motives of Rahami, who was charged by Union County prosecutors with five counts of attempted murder in the first degree and two second-degree weapons charges.

More charges were expected to be brought against Rahami in federal court. New York’s mayor called the bombing that injured 29 people in the bustling Chelsea district “an act of terror.”

Rahami, who lived with his family above the First American Fried Chicken restaurant in Elizabeth, New Jersey, is also suspected of planting a bomb that exploded on the New Jersey shore on Saturday, a device found near the New York blast, and up to six more devices found near the Elizabeth train station on Sunday night.

The bombings and subsequent manhunt prompted even greater security in America’s biggest city, already on high alert for a gathering of world leaders at the United Nations in New York for the annual General Assembly this week. An additional 1,000 officers were deployed.

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While officials did not give much information about Rahami, CNN, citing unnamed law enforcement sources, reported that Rahami traveled multiple times to Afghanistan and Pakistan in recent years, including a year-long stay in Pakistan until March 2014. Police were looking into whether he was radicalized overseas, CNN said.

The New York Times reported that no evidence had yet been found that Rahami had received military training overseas but said FBI agents were trying to determine if his actions had been guided by Islamic State militants or any other terrorist organization.

U.S. security sources have confirmed that the suspect underwent secondary screening after returning from foreign travel in recent years and passed on every occasion.

Sources, however, could not immediately confirm that Rahami traveled to Pakistan and Afghanistan, as other media have reported. Travelers coming from places such as those two countries are routinely required to undergo secondary screening.

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The blasts, the manhunt and an apparently unrelated stabbing attack in Minnesota over the weekend created tensions similar to those that followed other recent attacks, such as the mass shootings in Orlando and San Bernardino, California.

The Minnesota attacker was described a “soldier of the Islamic State,” the militant group’s news agency said.

Rahami had not previously been identified as dangerous but his family was known to police as a result of late-night noise and crowd complaints at a family halal chicken restaurant in Elizabeth.

The events also fueled the debate about America’s security challenges seven weeks before the presidential election, with candidates Donald Trump and Hillary Clinton clashing once again on Monday.