NOGALES, Mexico – The migrants walk for days through miles of mesquite scrub, running low on food and sometimes water, paying armed drug thug “guides” and dodging U.S. law enforcement officers along the way. And still they keep coming.

The latest figures show that Arizona, which is about to put into effect the nation’s toughest immigration law, also is the only border state where illegal crossings are on the rise.

While tightened security and daunting fences in Texas and California have made Arizona a busy crossing corridor for years, migrant smugglers now are finding new ways through the state’s treacherous deserts.

Carmen Gonzalez, 27, recalled seven days and six nights of walking with her husband in the desert and being accosted by Mexican thugs with AK-47s, who demanded $100 bribes. They were later arrested at a safe house in Arizona.

“I won’t try again because we went through too much suffering in the desert,” Gonzalez said at a shelter in this Mexican border town, where she, her husband and her brother were staying after being deported.

New U.S. Border Patrol statistics show arrests on the Arizona border were up 6 percent — by about 10,000 — from October to April, even as the apprehension of illegals dropped 9 percent overall. The agency uses arrests to gauge the flow of migrants; there are no precise figures on the number of illegal crossings.

Statistics from the Mexican side also show a rise in illegal crossings through Arizona.

Grupo Beta, a Mexican government-sponsored group that aids migrants, helped 5,279 people from January to April in the area across the border from Douglas, Ariz., compared to 3,767 in the same period last year, said agent Carlos Oasaya.

That’s the same area where Arizona rancher Robert Krentz was fatally shot in March. Authorities suspect an illegal immigrant who was headed back to Mexico and worked as a scout for drug smugglers.

The killing helped fuel the emotion around the Arizona law, which will empower police to question and arrest anyone they suspect is in the country illegally. It takes effect in July.

Immigration is likely to be at the top of the agenda today when Mexican President Felipe Calderon visits Washington and attends a state dinner at the White House. Calderon has condemned Arizona’s law; President Obama has called it “misguided” and vowed to begin tackling an immigration overhaul.

Supporters of the Arizona law said Tuesday that the growth in arrests at the border didn’t spur its passing.

Instead, it was a series of factors, including the discovery of a growing numbers of immigrant safe houses and a rise in crime by illegal immigrants who have injured and killed police officers, said state Rep. John Kavanagh, R-Fountain Hills.

In the 1990s, increased enforcement and corrugated metal and chain-link fences dramatically cut illegal border crossings in California and Texas.

Overall, illegal immigration through those two states, New Mexico and Arizona has declined from nearly 1.2 million in 2005 to 541,000 in 2009, according to the Border Patrol. In Arizona, illegal crossings fell from 578,000 in 2005 to nearly 250,000 last year — before the recent rise.

Immigration experts have long predicted that the decline in crossings would reverse as the U.S. economy recovers.

“The fact is that as long as there remains an economic disparity between the U.S. and Mexico and other Latin American countries, enforcement and sanctions and any other measure won’t stop the flow of migrants,” said Charles Pope, interim director of the Trans-Border Institute at the University of San Diego.