On the first day of what was supposed to be tighter screening ordered by the United States for airline passengers from certain countries, some airports around the world have conceded they had not cracked down.

The U.S. demanded more careful screening for people who are citizens of, or are flying from, 14 nations deemed security risks. But enforcement of the U.S. rules appeared spotty Monday.

“Everything is the same. There is no extra security,” said an aviation official in Lebanon, one of the countries on the list. The official spoke on condition of anonymity because he was not authorized to speak publicly.

The administration of President Barack Obama ordered the changes after what authorities say was a failed attempt by a Nigerian man to blow up a jetliner bound from Amsterdam to Detroit on Christmas Day.

The U.S. Transportation Security Administration said the enhanced screening techniques would include full-body pat-downs, searches of carryon bags, full-body scanning and explosive-detection technology.

On Monday, passengers arriving on international flights reported they had been patted down individually, or had their luggage inspected by hand — steps that have been in place on many international flights since the failed bombing.

Passengers on a flight from Stockholm to Newark, N.J., were patted down and had their bags checked at the gate, flier Mark Biddle said. He said no passengers had been singled out for special attention.

In Nigeria, one of the nations on the U.S. list for additional security, there were long lines on the first day of the new rules. At the airport in the capital of Lagos, Mine Oniovosa, a 24-year-old student, said she had been told to show up more than seven hours ahead of time for a flight to Atlanta.

A Nigerian official pledged that everyone would be patted down at the country’s international airports. In Lagos, guards wearing latex gloves combed through bags, spending more than a minute on each one.

But at international airports in Lebanon, Syria and Libya, all on the list, there were no visible changes in screening. And several European governments, including Germany, France and Spain, said they were still studying the rules before tightening security any further than the steps they took after the failed Christmas attack.

“We will continue to work with our airline and international partners to ensure they meet both international and TSA security standards,” said Greg Soule, spokesman of the U.S. Transportation Security Administration.

Among the 14 nations are four — Cuba, Iran, Sudan and Syria — that the U.S. government considers state sponsors of terrorism. The list also includes Afghanistan, Algeria, Iraq, Lebanon, Libya, Nigeria, Pakistan, Saudi Arabia, Somalia and Yemen.

Passengers arriving at U.S. airports on international flights described a wide range of screening methods — from being separated by gender and patted down to nothing more invasive than normal airport security.

If the security measures are not followed, the U.S. Transportation Security Agency can penalize the airlines, according to a TSA official who was not authorized to speak about the enforcement rules. The penalties could include warnings and fines, and recalcitrant airlines could ultimately be barred from flying to the U.S.

In Cuba, the Communist Party newspaper Granma denounced the new airport security measures adopted by the United States as a product of “anti-terrorist paranoia.” Cuba is one of 14 countries affected by the new measures because Washington considers the island a state-sponsor of terrorism.

A U.S. intelligence official said the government had moved the names of dozens of people onto its terrorism watch list and its no-fly list after reviewing the government’s database of suspected terrorists.

The man arrested in the Christmas incident, Umar Farouk Abdulmutallab, had been in a database with about 550,000 other terror suspects since late November. But officials said the government did not have enough information to put him on the no-fly list.

While screening for international flights has been tightened, there have been few changes at domestic airports.

On Sunday, officials at the Newark airport emptied a terminal and forced passengers to go through screening again after a man passed through a security checkpoint going the wrong way. His identity and whereabouts remained unknown Monday.

Saudi Arabia said it had placed additional security personnel at its airports, and a Nigerian minister said the government there would perform whatever security checks the U.S. asked for.

“It is for the good of everybody that everybody is searched thoroughly,” Information Minister Dora Akunyili said.

Still, she questioned Nigeria’s inclusion on the list. While Abdulmutallab is Nigerian, she noted he had lived and studied abroad for years.

“It is unfair to discriminate against 150 million Nigerians over the behavior of one person,” Akunyili said. “It is outside of the shores of this country that he developed this nasty tendency to do what he tried to do.”