Police in London announced on Tuesday that they are investigating parties held during a lockdown at the office and residence of Prime Minister Boris Johnson. A senior civil servant was already looking into the gatherings.

Johnson has apologized before Parliament for joining a party in May 2020 at his residence. Now, a broadcaster is reporting he attended another to mark his birthday.

ITV News reports that, in June 2020, Johnson attended the party with about 30 staff inside his office. The broadcaster said, afterward, he hosted friends at his residence. At the time, he had banned social gatherings indoors.

His staff said Johnson was at the party for less than 10 minutes. They said he then hosted a few members of his family outdoors.

Johnson said he welcomed the decision by police to conduct their own investigation. He said it would help give the public "clarity." But even members of his own party are calling on him to resign.