Updated 7:12 p.m. | Middlesex County Sheriff Peter Koutoujian and state Sen. Katherine Clark, two of the five Democrats running in an upcoming special election primary in Massachusetts’ 5th District, raised more than $600,000 each in the past three months.

Koutoujian raised about $610,000, while Clark pulled in $616,000, which includes a $250,000 personal loan to her campaign, according to reports filed with the Federal Election Commission. Koutoujian reported $690,000 in cash on hand less than two weeks out from the Oct. 15 primary, while Clark reported $390,000.

According to Koutoujian’s campaign, about $560,000 of the funds raised in that three-month period are designated for the primary. The remaining $40,000 is reserved for a general election, according to federal campaign finance law.

Clark’s campaign says that of the $390,000 in cash on hand it has, $283,000 is designated for the primary.

Both Clark and Koutoujian’s fundraising hauls dwarf that of state Rep. Carl Sciortino, the only other Democrat in the race to have filed a report so far. Sciortino reported raising $265,000, with $285,000 in cash on hand going into the primary.

All eyes now are on the primary’s other front-runner: state Sen. Karen Spilka.

All of the candidates are fighting to succeed Edward J. Markey, who was elected to the Senate in June.

Whoever emerges from the Democratic primary will be the next member of Congress from this heavily Democratic district located in the Boston suburbs. Massachusetts’ 5th District is rated a Safe Democratic contest by Rothenberg Political Report/Roll Call.