Sen. Claire McCaskill, D-Mo., told constituents over the weekend that she'd suffered a cracked rib after a colleague saved her from choking at a Democratic caucus luncheon - an injury that took that colleague, Sen. Joe Manchin, D-W.Va., by surprise.

On Friday, as she made the rounds at an NAACP dinner in Missouri, McCaskill said that she would not be hugging people who came up to her, after Manchin accidentally injured her rib.

A spokesman for Manchin said that the accident occurred on Thursday, when Senate Democrats met for lunch, a gathering that usually excludes most staffers. McCaskill began choking, and Manchin ran over to give her the Heimlich maneuver. That dislodged the blockage in McCaskill's throat, but unbeknownst to Manchin, it left his colleague injured. McCaskill participated in the day's final votes, and then traveled home to Missouri.

McCaskill's office did not answer a further question on the incident, but she kept up her campaign schedule over the weekend, addressing Democrats on Saturday evening at their annual dinner.

Manchin and McCaskill are seen as two of the most vulnerable Senate Democrats up for re-election this year, after President Donald Trump won both of their states with landslide margins.