WASHINGTON (AP) — Former Sen. Rick Santorum moved into second place Tuesday in the race for delegates with wins in Republican presidential caucuses in Colorado and Minnesota.

Santorum picked up at least 28 delegates while former Massachusetts Gov. Mitt Romney got at least six.

Overall, Romney has 107 delegates, including endorsements from members of the Republican National Committee who automatically attend the party's national convention and can support any candidate they choose. Santorum has 45 delegates, Newt Gingrich has 32 and Ron Paul has nine.

The race for delegates is still in the early stages. It will take 1,144 delegates to win the GOP nomination.

Santorum also won the Missouri primary Tuesday, but the party is not awarding any delegates based on the results. Instead, Missouri will award its 52 delegates through a system of caucuses and conventions, starting March 17.

Minnesota had 37 delegates up for grabs Tuesday — 13 based on statewide results and 24 based on results in individual congressional districts. Colorado had 33 delegates at stake — 12 based on the statewide vote and 21 based on results in individual congressional districts.

Delegates to the party's national convention from Minnesota and Colorado are not bound by the results of Tuesday's caucuses. The caucuses were the first step of a multi-step process to award the delegates.

However, an Associated Press analysis showed Santorum would win all 13 of Minnesota's statewide delegates if he maintains the same level of support throughout the process. The district delegates could not be determined on election night because Minnesota has not approved new congressional district boundaries following the 2010 Census.

Santorum and Romney split Colorado's 12 statewide delegates, according to the AP analysis. Santorum also won nine congressional district delegates in Colorado.

The remaining 12 delegates in Colorado could not be determined on election night because the party did not provide votes by congressional district for counties that are split into multiple districts.

The Associated Press calculates the number of national convention delegates won by candidates in each presidential primary or caucus, based on state and national party rules. Most primaries and some caucuses are binding, meaning delegates won by the candidates are pledged to support that candidate at the national conventions this summer.

Political parties in some states, including Minnesota and Colorado, use local caucuses to elect delegates to state or congressional district conventions, where national delegates are selected. In these states, the AP uses the results from local caucuses to calculate the number of national delegates each candidate will win, if the candidates maintain the same level of support.

The AP will update delegate totals, if support for the candidates changes. The AP also interviews RNC delegates, who can support any candidate they choose, to see which one they support.