Voters and civil rights groups reported long lines, isolated cases of malfunctioning equipment and some harassment at polling places in Tuesday's U.S. presidential election, but fears of widespread violence at the polls did not materialize.

Nationwide, civil rights groups logged unusual levels of voter intimidation complaints, receiving about 20,000 calls through a national voter complaint hotline as of Tuesday afternoon. Democratic Party officials, however, said they did not see systemic voter suppression efforts.

Civil rights groups, who have enlisted 7,000 volunteers, said 40 percent of the calls they had received through a telephone hotline by early afternoon were from African-American and Latino voters.