JOHN YANG: In tonight's other news, Russia and Ukraine exchanged hundreds of prisoners today just hours after a large scale Russian attack on Kyiv.

At least 15 people were injured when Russia launched ballistic missiles and drones into Ukraine's capital.

The mayor said air raid sirens warned of the incoming attack, which damaged apartment buildings and a mall.

Across Ukraine, 13 people were killed in other ballistic missile attacks.

Russia later said it hit only military targets.

Hours later, the two countries exchanged hundreds of soldiers.

Each side said 300 military personnel were repatriated and that there may be another swap tomorrow.

If there is, it could make this weekend's exchanges the biggest since Russia's full scale invasion three years ago.

There's been a major restructuring of President Trump's National Security Council under interim National Security Adviser Marco Rubio, the secretary of state.

PBS News has learned that dozens of NSC staff members have been removed from their roles, including the deputy National Security Advisor and the senior directors of Europe and the Middle East.

Many of the positions will not be filled.

Since its creation in 1947, the NSC has traditionally played a big role in developing a president's diplomatic and security policies, coordinating with the State and Defense departments.

The U.S. measles outbreak has passed a milestone.

The CDC says that more than 1,000 confirmed cases have been reported in 31 states.

96 percent of the patients are either unvaccinated or their vaccination status is unknown.

Most of the confirmed cases have been in West Texas.

Across Texas, 728 cases have been reported.

The CDC says the MMR vaccine, which protects against measles, is very safe and effective.

And another milestone for tennis star Novak Djokovic, his victory today in the Geneva Open is his 100th career singles title.

Djokovic, who turned 38 on Thursday, powered his way to victory in three sets.

He later said he felt like he was trailing most of the match.

Djokovic is just the third man to win 100 titles in the Open era, after Jimmy Connors and Roger Federer.

And caretakers at a San Diego wildlife center are going to great lengths to rehabilitate a young black bear cub.

The two-month old was found by campers last month, weak and malnourished.

The area was monitored in hopes that his mother would return, but she never did.

Now wildlife center workers are playing that role, giving him around the clock care.

They wear a bear suit so that the cub doesn't bond with humans.

They'll care for the cub for about a year before attempting to release him back into the wild.

Still to come on PBS News Weekend, the effect preteen social media use may have on their mental health and do taxes on sodas and sugary drinks result in better health outcomes.