Update: The preliminary report is out, and Al Jazeera seems to be reporting the news independently, as well. Safiya and Aisha Qaddafi were apparently accompanied "by a Libyan delegation," and are now on the island of Djerba. They actually reached Tunisia on Saturday, the 14th. You may recall Aisha Qaddafi as the woman who gave a rousing address to a Libyan crowd back in mid-April, insisting: "Gaddafi said if the Libyan people don't want me I don't deserve to live. The Libyan people responded, 'He who doesn't want you does not deserve life'."

The Telegraph's Andrew Gilligan also points out that this is a lot of Qaddafis in Tunisia, now:

Arab newspapers claimed on Tuesday that Gaddafi's eldest son, Muhammed Muammar Gaddafi, had also left the country for "medical treatment" in Tunisia, along with other officials including the head of the customs agency and the country’s representative to the Arab League.

Original post: Reuters is reporting in a banner across its site, that Muammar Qaddafi's wife and daughter, Safiya and Aisha, respectively, have crossed the border from Libya into neighboring Tunisia. The source appears to be Tunisian security forces. We'll update as the reports start to come in.