Thousands of Haitian undocumented immigrants lined up outside government offices in the Dominican Republic Tuesday racing a deadline to register with the authorities or face deportation.

The Dominican government has given undocumented immigrants -- the vast majority of whom are from Haiti next door, the poorest country in the Americas -- until Wednesday to submit papers under new rules to regularize their status.

But those standing in the long lines under the hot sun said the deadline was impossible to meet, as rights groups estimated that some 200,000 Haitians would be left facing deportation.

"I've been coming here for five days, and haven't managed to get in," said Jean Claude Jodias as he stood outside the interior ministry.

"In the morning, I got through the entrance. But the police kicked me out and I couldn't fight them. I gave a man 500 pesos ($10) to get me in, but I never saw him again," said Jodias, a construction worker who has lived in Santo Domingo, the Dominican capital, for the past 10 years.

An estimated 458,000 Haitians live in the Dominican Republic, often laboring in the sugar cane fields or as domestic workers.

They make up nearly 90 percent of the country's immigrants and 5.4 percent of the total population. Just one in 10 has legal status.

As the deadline approaches, Haitian men, women and children have been lining up outside the interior ministry's gates day and night, through drizzling rain, morning chill and midday heat of 35 degrees Celsius (95 Fahrenheit).

Similar scenes have played out at registration centers across the country, where the immigrants have until 7:00 pm Wednesday to turn in their paperwork.

"Those who do not register under the regularization plan... are subject to deportation," said Deputy Interior Minister Washington Gonzalez.

The so-called National Plan for the Regularization of Foreigners is the latest source of tensions between the Dominican government and the Haitians who have sought to carve out a better life in the country next door and escape chronic poverty and instability at home.

Haitians have long been targets of resentment and racism, which boiled over into the massacre of thousands of them in 1937 under the orders of Dominican dictator Rafael Trujillo.

- Confusion on rules -

Mariamis Crousef, who had spent the night in line, was awaiting her turn with her 18-month-old daughter.

She complained, like many of those waiting, that Haitian authorities were dragging their feet in delivering her the required identity document.

"I applied for our papers in November and I still haven't received them," she said.

Those who have managed to get inside and begin the paperwork often do not realize they no longer need to beat the deadline.

They wait in line with the rest, even though the government has said that those who have begun the process by Wednesday will have a year to complete it.

The interior ministry estimated that 250,000 foreigners would register, between 94 and 96 percent of them Haitian.

The government, which has been accused of violating deported Haitians' rights, says it has invested in buses and holding centers to ensure decent treatment of those who will be deported.