Nearly one in three people with Somali ancestry in the United States now live in the Minnesota, which has the largest concentration in the country, according to government data released Tuesday.

The latest report from the U.S. Census Bureau's American Community Survey found about 25,000 of the 85,700 Somalis in the U.S. live in Minnesota. Ohio, Washington and California also had large populations of Somalis, but the survey data found no more than 10,500 of them in any state except Minnesota.

There, the Somali population is growing, Minnesota State Demographer Tom Gillaspy said. The 2000 Census pegged it at 11,164.

The proof is on the streets of the Twin Cities, said Hashi Shafi of the Somali Action Alliance in Minneapolis.

Minneapolis Public Schools reported 1,345 of the district's students spoke Somali at home during the 2008-2009 school year, and Shafi said the number is growing every year.

He remembers a time when there were only two mosques in Minneapolis _ now he can point to four on one block.

"When you come on Friday, they are all full," he said.

Shafi said Somalis often estimate their own population in Minnesota at about 70,000, but he didn't know what that was based on. He has worked with the Census Bureau to overcome cultural and language barriers to get more Somalis counted.

"People don't know why this is important," he said, noting that government funding is often based on census data.

Gillaspy said the federal estimate, which includes people born in Somalia and their descendants, was in line with the state's, although based on different sources. The information released Tuesday came from five years of surveys, and Gillaspy said it provides the best look at small population groups and small geographic areas since the 2000 Census.

The American Community Survey is sent to about one in 10 households each year. It includes questions on ancestry, national origin and many other traits that are no longer asked about in the census done every 10 years.

The exodus from Somalia began after the Horn of Africa nation fell into lawlessness in 1991. Thousands of Somalis began to settle in the U.S., usually in cities with nonprofit groups that would help them.

In many communities _including Minneapolis, Seattle, San Diego, and Columbus, Ohio _ the population has grown and prospered, with Somali-owned shops and mosques proliferating. Somali translators work in the schools, the children of refugees go on to college and community leaders become public figures.

But there have been worrying signs about the second generation, with reports out of Minnesota of Somali gangs running interstate prostitution rings and investigations of young men going to fight with al-Shabab, which seeks to establish an Islamic state in Somalia.

Ahmed Sahid, president of Somali Family Services of San Diego, said the local population there was swelling with a "second migration" driven by Somalis leaving cold parts of the United States.

The government estimates there are 5,000 Somalis in the San Diego area, but Sahid said estimates are often wrong, and he thought there were 15,000 to 20,000.

"A lot of people don't know how to report themselves," he said last week. "I don't think the Census will show a true figure of the population."

The population is growing in Seattle, too, with the survey estimating it at about 8,600.

Bernardo Ruiz, manager of community and family partnerships for the Seattle public schools, said four years ago, Somali was the fourth most common foreign language spoken at home by students in the schools. Three years ago, it was third. Now, it's second after Spanish with, by the district's count, 1,680 students.

In response to the growth, the district has created a variety of support services including bilingual tutoring and a Saturday school that teaches English, math and life skills. It also hired Mohamed Roble, a Somali elder who works with families from Somalia and other East African countries.

Roble said he sees a second wave immigration into the area from Minneapolis and other Somali communities around the United States. He said Somalis were coming to Seattle partly to escape violence in other American cities.

"We don't have a lot of gangs like Minnesota or San Diego," he said.