Judge Marsha Revel determined that the 23-year-old actress' bail should be raised after receiving results from the court-ordered alcohol monitoring bracelet. It is unclear what caused the bracelet to go off. A prosecutor and Lohan's lawyer told the AP earlier Tuesday they were awaiting information about that.
The bracelet is designed to test the skin for alcohol every half-hour by sampling a person's perspiration, and there are sensors that check for tampering.
Lohan appeared at MTV's Movie Awards Sunday, and the AP reported that she attended at least one of the after-parties.
Upon her return from Cannes, Lohan appeared in court where Revel issued mandatory drug testing along with the bracelet, which Lohan must continue to wear until a July hearing.
Lohan has been on probation since August 2007 after pleading guilty to drug charges and no contest to three driving charges.