BOSTON (AP) — One of the top two finishers in a 10-way Democratic primary for an open U.S. House seat in Massachusetts plans to ask for a recount.

Dan Koh said in a statement his campaign will file for a recount by Friday's 5 p.m. deadline.

Unofficial returns from 100 percent of the precincts in the district showed Lori Trahan leading Koh by 52 votes, out of approximately 85,000 votes cast Tuesday.

Koh's campaign said "significant changes in vote counts in some communities over the last couple of days have made it clear that a recount is necessary to ensure every vote is counted."

A Trahan spokesman said her campaign was also collecting signatures for a possible recount.

They are vying to replace Democratic U.S. Rep. Niki Tsongas, who didn't run for re-election.