Domestic and international travelers were arriving early for flights out of the Islands yesterday — one of the busiest travel days of the year — as authorities beefed up security at airports statewide, increasing patrols of bomb-sniffing dogs and upping scrutiny at checkpoints.

The heightened security measures so far haven't translated into longer lines at Hawai'i airports, as they have on the Mainland, and officials say that's partly because of travelers coming early and coming prepared. But officials warned that long security lines and other headaches are still a possibility, since airports remain busy with holiday travelers through New Year's.

"We are recommending that they do give themselves more time" to get through security checkpoints, said state Transportation Director Brennon Morioka. "TSA is going to be more vigilant in their security checks. There is the potential for slightly longer waits."

The heightened security comes in the wake of a failed Christmas Day plot to blow up a Detroit-bound airliner — an incident President Obama yesterday called an "attempted act of terrorism" and a "serious reminder" of the need to continually adapt security measures against changing terrorist threats.

Obama, speaking to reporters at Marine Corps Base Hawaii at Käne'ohe Bay, also vowed to use "every element of our national power" to keep Americans safe and "defeat the violent extremists who threaten us."

"It's absolutely critical that we learn from this incident," he said.

'PEACE OF MIND'

At Honolulu International Airport yesterday, passengers said they were happy to see new security measures in place and felt safer because of them. They also said they were doing their part to move through security lines quickly by arriving earlier and double-checking their luggage to make sure they had nothing that couldn't go aboard, such as more liquid than is allowed.

The heightened security "keeps our peace of mind," said 50-year-old Jamie McSporran of Edmonton, Alberta, who was traveling with 13 members of his family after a vacation in Hawai'i.

The group arrived at the airport about 2 1/2 hours early for their flight home.

The new security "certainly is in our best interests," McSporran said.

Brian Sekiguchi, DOT deputy director for state airports, said part of the emphasis of the heightened security is on "roaming security." At Honolulu International Airport, Morioka said, travelers are seeing more patrols of state deputy sheriffs and bomb-sniffing dogs in terminals. Security guards were also randomly checking cars heading into airport parking garages.

MORE FOOT PATROLS

Meanwhile, Neighbor Island airports have stepped up foot patrols of hired security guards.

And scrutiny at Transportation Security Administration checkpoints at all airports has increased, Morioka said. Travelers heading to the Neighbor Islands, domestic destinations and foreign soil all have to go through a TSA checkpoint, where their carry-on luggage is X-rayed and they are asked to walk through a metal detector. They can also be pulled aside to be screened.

All checked luggage is also X-rayed after being taken at the ticket counter.

"They're looking for explosive devices" and other contraband, said Sidney Hayakawa, the former head of TSA in Honolulu who now is in the administrative services office in the airports division. He added TSA has been issued "security directives," some of which travelers won't see.

He would not discuss those measures, but said they were in line with other security efforts.

Hayakawa added that travelers are also being asked to be vigilant and report suspicious activity.

Several travelers at Hono- lulu Airport yesterday said they were trying to be more aware of their surroundings and on the lookout for anything peculiar. "We have a heightened awareness," said Joan Ehmen, who was heading back to Atlanta with her husband and two children.

The family got to the airport about two hours early for their flight through Los Angeles.

"We're expecting there are going to be some changes" to security, she said.

Kristin Hingtgen, 25, of Seattle, said she is also trying to keep her eyes open for anyone suspicious. "I think that's just natural," she said. "I guess everybody will probably be doing that."

HEARING POSTPONED

The man behind the Christmas Day incident — Umar Farouk Abdulmutallab — charged with trying to destroy an aircraft, is being held at a federal prison in Milan, Mich. A court hearing that had been scheduled for yesterday to determine whether the government can get DNA from him was postponed until Jan. 8. No reason was given.

Meanwhile, al-Qaida in the Arabian Peninsula has claimed responsibility for the thwarted attack as retaliation for a U.S. operation against the group in Yemen.

Yemeni forces, helped by U.S. intelligence, carried out two airstrikes against al-Qaida operatives this month in the lawless country that is fast becoming a key front in the war on terror. The second one was a day before 23-year-old Abdulmutallab attempted to bring down a Northwest Airlines flight as it prepared to land in Detroit.