Governments throughout Mexico and Central America are on alert as evidence grows that al-Qaida members are traveling in the region and looking for recruits to carry out attacks in Latin America - the potential last frontier for international terrorism.

The territory could be a perfect staging ground for Osama bin Laden's militants, with homegrown rebel groups, drug and people smugglers, and corrupt governments. U.S. officials have long feared al-Qaida could launch an attack from south of the border, and they have been paying closer attention as the number of terror-related incidents has increased since last year.

The strongest possible al-Qaida link is Adnan G. El Shukrijumah, a 29-year-old Saudi pilot suspected of being a terrorist cell leader. The FBI issued a border-wide alert earlier this month for Shukrijumah, saying he may try to cross into Arizona or Texas.

In June, Honduran officials said Shukrijumah was spotted earlier this year at an Internet cafe in Tegucigalpa, the capital of Honduras. Panamanian officials say the pilot and alleged bombmaker passed through their country before the Sept. 11 attacks on the United States.

U.S. Attorney General John Ashcroft in May singled out Shukrijumah as one of seven especially dangerous al-Qaida-linked terror figures wanted by the government, which fears a new al-Qaida attack. A $5 million reward is posted for information leading to his capture.

Mexican and U.S. border officials have been on extra alert, checking foreign passports and arresting any illegal migrants. In a sign of a growing Mexican crackdown, eight people from Armenia, Iran and Iraq were arrested Thursday in Mexicali on charges they may have entered Mexico with false documents, although they did not appear to have any terrorist ties.

Jose Luis Santiago Vasconcelos, Mexico's top anti-crime prosecutor, said Mexican officials have no evidence that Shukrijumah - or any other al-Qaida operatives - are in Mexico. But Mexican authorities are investigating and keeping a close eye on the airports and borders.

"The alert has been sounded," Vasconcelos told The Associated Press last month.

In Central America, Honduran Security Minister Oscar Alvarez said officials have uncovered evidence that terrorists, likely from al-Qaida, may be trying to recruit Hondurans to carry out attacks in Central America. He did not offer details.

El Salvador authorities last week reinforced security at the country's international airport and along the borders after purported al-Qaida threats appeared on the Internet against their country for supporting the U.S.-led coalition in Iraq. President Tony Saca, undeterred, is sending the country's third peacekeeping unit - 380 troops - to Iraq.

Terrorists have struck in Asia, Europe, Africa, the Middle East and the United States. Latin America could be next, analysts say, especially as it becomes harder to operate elsewhere.

"If there is a crackdown, they are going to pick up shop and move," said Matt Levitt, a terrorism analyst and senior fellow at the Washington Institute.

Officials worry the Panama Canal could be a likely target. In 2003, boats making more than 13,000 trips through the waterway carried about 188 million tons of cargo.

Earlier this month, the United States and seven Latin American countries - including Argentina, Chile, Colombia, the Dominican Republic, Honduras, Peru and Panama - carried out a weeklong anti-terror exercise aimed at protecting the canal.

In South America, U.S. officials have long suspected Paraguay's border with Brazil and Argentina as an area for Islamic terrorist fund-raising. Much of the focus has fallen on the Muslim community that sprouted during the 1970s, and authorities believe as much as $100 million a year flows out of the region, with large portions diverted to Islamic militants linked to Hezbollah and the Palestinian militant group Hamas.

The more immediate concern is Mexico, which shares a porous, 2,000-mile border with the United States and is the home to widespread organized crime.

In December, Mexican officials canceled two Aeromexico flights from Mexico City to Los Angeles, and a third was forced to turn around after takeoff because of terrorism concerns.

At the time, the United States, Canada and Interpol told Mexico that officials suspected terrorists might be using Mexican soil to plan an attack, Vasconcelos said.

Concerns increased this summer about whether Mexico was doing enough to screen international visitors after a 48-year-old South African woman arrived in Mexico with a passport that was missing several pages and then waded across the Rio Grande into Texas.

Farida Goolam Mahamed Ahmed was arrested July 19 while trying to board a flight in McAllen, Texas. She pleaded innocent Friday to immigration violations and was under investigation for links to terrorist activities or groups. Court testimony indicated she traveled from Johannesburg on July 8, via Dubai, United Arab Emirates, to London, then to Mexico City on or about July 14. The countries she traveled through do not require South Africans to have visas.

Mexican officials said Ahmed was not stopped upon entering Mexico because her name did not appear on any international terrorist watch-lists.

Mexican officials say they are closely scrutinizing visa requests from the Middle East and have heightened surveillance at the nation's largest airports since Sept. 11.

"The requirements for a visa for people from the Middle East have not changed, but all requests are being checked more thoroughly," said Mauricio Juarez, a spokesman with Mexico's Migration Institute.

The country is a popular U.S. entry point for people trying to sneak into the United States, and the majority - 46 percent - of all people arrested on immigration violations in Mexico come from Brazil. The rest are largely from the Americas, China or Singapore.

It has become nearly impossible for people from Muslim countries to get visas to come to Mexico since the Sept. 11 attacks.

Fayesa Amin, a 37-year-old Pakistani, started the process to get a Mexican visa two months before she was to attend a wedding in Mexico. The Mexican consulate in Karachi asked her to fill out several forms and to turn in copies of her credit card and bank statements for a full year.

Amin, who runs three beauty salons in Pakistan, said Mexican authorities told her a visa had been approved and it could be picked up in London. But Mexican officials there said her visa was being held in Ankara, Turkey. In the end, she ended up spending her holiday stranded in London.

"I knew it would be hard to get to that part of the world and that everything had become more difficult," Amin said in a telephone interview from Islamabad. "But I didn't realize how hard it could be."

By Olga R. Rodríguez