Google Plus iconGoogle+, Google’s brand-new social networking site, will once again let users invite their friends to join them on the site, Google’s senior vice president of engineering Vic Gundotra said.

Google closed invitations for its social networking site due to “insane demand” on Wednesday last week. The site launched on Tuesday last week to a small number of users, and then publicly on Wednesday. At the time, anyone could invite their friends, leading to a massive amount of new users flocking to the site.

“Please invite carefully,” Gundotra said on his Google+ feed.

The company is still throttling invitations, according to Google’s engineering director Dave Besbris. That means people trying to invite a massive number of people to the service will probably get their invitation privileges shut off, he said.

“We continue to throttle invites, so please don’t mass invite folks as it won’t work,” Besbris said. “If you invite a handful of your most important friends and family you’re much more likely to get these folks into our system.”

Google will continue to roll out the social networking service slowly to make sure its infrastructure can handle the load from the large number of individuals that want access to the site. The site is also working through bugs as they are reported and wants them to be fixed quickly, Besbris said.

“Things are going well with the systems right now so we feel comfortable enough to open up invites for a brief period,” he said. “Our goal is to double the user base in the field trial.”

Besbris wouldn’t comment on how many users have already signed up for Google+.