A day after a Twitter post linked Maine to Saturday’s terrorist attack in a mall in Nairobi, Kenya, law enforcement officials refused to say whether they are investigating the possibility that radical Islamist groups are trying to recruit new members in the state.

Gunmen from the Somali group al-Shabab attacked the Westgate mall in Nairobi, killing at least 62 people and taking an unknown number of hostages. On Sunday, a list of 17 supposed attackers and their home towns or states was posted on a Twitter account purportedly run by al-Shabab. One was listed as being from Maine.

The list surprised many in law enforcement who scrambled Monday to determine its authenticity.

“There’s still no confirmation of the names that were out there on Twitter that were alleged to have been from the U.S.,” said Paul Bresson, a spokesman for the FBI in Washington. “We don’t have the identities confirmed.”

Bresson would not say what the bureau was doing to verify the list or confirm whether the Twitter post came from al-Shabab.

The Washington Post reported that al-Shabab said it had not issued the tweet and had not released names or any other details about the people in the attack. That was verified by a group that tracks extremist groups, the Post reported.

The Kenyan foreign minister, Amina Mohamed, told PBS NewsHour that “two or three” Americans are among the gunmen. He described them as “young men … between maybe 18 and 19,” of Somali or Arab origin.

However, early in the day, BBC reported on Twitter that Abu Omar, al-Shabab’s military commander in Somalia, denied that any “Britons or Americans” had participated in the attack.

Even before the list was published, terrorism analysts and a congressional leader on terrorism issues, Rep. Pete King, R-N.Y., said the FBI should be probing communities including Portland for possible recruitment of al-Shabab terrorists.

King said al-Shabab has recruited as many as 50 people from Somali-American communities and 15 to 20 of them remain active.

For its size, Maine has a large population of Somali immigrants. But the Somali communities in Portland, Lewiston and Auburn are much smaller than those in some other states.

Portland Mayor Michael Brennan said he knows of no efforts by terrorists to recruit in the city.

“I’ve never been informed by Portland police or other law enforcement there has been that activity in the city,” Brennan said. “We have been in touch with the police department. At this point, we don’t know anything more than the allegation.”

Police Chief Michael Sauschuck said that anything terrorism-related is under federal jurisdiction. He did say that his department and the FBI have communicated, but he would not describe what local officers are doing to support a federal investigation.

“I don’t want to talk about anything operationally,” Sauschuck said. “The radicalization of individuals stateside has been a concern of the federal government for some time and they’ve passed along those concerns to law enforcement officers nationally.”

Members of Maine’s congressional delegation treaded carefully around the issue on Monday.

The office of Rep. Chellie Pingree, a Democrat whose district includes Portland, had been in touch with the FBI, the State Department, the Department of Homeland Security and other federal agencies.

In a prepared statement, Pingree said it is important not to jump to conclusions about possible terrorist connections to Portland.

Pingree’s spokesman Willy Ritch indicated later that the office had not been presented with definitive evidence either way.

“The message we were left with from all of the briefings Chellie’s office received is that, in these situations, these claims of responsibility are not always true and we need to be very careful about making any assumptions about the validity of them,” Ritch said. “Nobody has told us that they are not valid or that they are not accurate. But at the same time, they have urged us to approach these reports with a healthy amount of skepticism.”

Pingree plans to meet with Somali leaders Tuesday in Portland.

Maine’s Sen. Angus King, an independent, has contacted Mayor Brennan in Portland and representatives of the Somali community.

“Angus’ staff has been in touch with counterterrorism officials who are following these developments closely and will keep him apprised of any new developments,” King’s spokeswoman Crystal Canney said Monday afternoon.

Canney would not provide additional details about King’s conversations with counterterrorism officials or say whether the FBI or other authorities had characterized the validity of reports suggesting a link between Maine and the al-Shabab attackers in Kenya.

State Department officials said Sunday night that they were aware of the reports of U.S. residents fighting for al-Shabab in Kenya but could not confirm those reports and were seeking more details. Reached Monday, a State Department official said she had no more information to release.

Law enforcement at the local and federal levels has worked to maintain lines of communication with immigrants from Somalia.

“I believe we have a good working relationship with the Somali community” in Portland, said Sauschuck.

Maine has been mentioned in past years as a possible recruitment site for al-Shabab.

Authorities say that more than 20 young men left Minnesota to join al-Shabab starting in 2007, when small groups of Somalis in Minnesota began holding secret meetings to talk about returning to their homeland to wage jihad against Ethiopians, according to The Associated Press.

The FBI has been aware of the threat since at least 2007. In 2011, an al-Shabab suicide bomber was traced to Minneapolis, where he had been recruited.

FBI officials in Portland said at the time that they were developing relationships with local Somali groups in hopes of learning of any efforts to radicalize and recruit. They also sought to address festering civil-rights issues that might make someone more vulnerable to radicalization.

“The idea that young males from any community, but particularly the Somali community, that radicalize themselves and go overseas to take up the fight — that has been a concern for a number of years,” said Bresson, of the FBI.

Bresson said he is not familiar with Maine’s Somali population or the degree to which recruitment might be a problem here.

At least one scholar of al-Shabab said he would not be surprised if the organization has attempted to recruit in Maine.

Josh Meservey, a Maine native, has spent the past several years studying al-Shabab, first while working with Somali refugees in Kenya, Ethiopia and other countries, and later as an academic. He focused on al-Shabab while pursuing a master’s degree in international relations from the Fletcher School at Tufts University, and now works as an independent researcher and writer in Washington.

“They’ve certainly focused a lot of energy on recruiting in the U.S. and in the West in general,” said Meservey. “Not only are they very effective in recruiting in the U.S., when those (individuals) go over there they utilize them as fighters. But they also use them as propaganda for the communities that these people left behind.”

Meservey said he has not seen any concrete evidence of recruiting in Maine, but when asked whether he believes the group has been active in the state, he said, “I think so.”

He said he wouldn’t be surprised to learn that Westerners were involved in the attack in Nairobi “because Shabab loves the propaganda value of that.”

The Waldoboro native said he has been watching the events with a heavy heart because he lived in Nairobi for several years and spent considerable time at that mall. He said he remembers sitting at a cafe there and talking with colleagues about their security concerns with the mall.

“There were so many (expatriates) there and wealthy Kenyans — it was such an easy target,” Meservey said.

The Associated Press contributed to this report.

David Hench can be contacted at 791-6327 or at:

dhench@pressherald.com