Russia is patrolling the Black Sea with submarines after its surface fleet got walloped, Ukraine says

• Russia is using four submarines to monitor the Black Sea, a Ukrainian official told national TV.
• Dmitry Pletenchuk said three were cruise missile carriers and that two "periodically" go to sea.
• Russia has ramped up the pace of its subs production, with one type worrying NATO officials.

Russia has started using submarines to patrol the Black Sea after suffering major naval losses, according to a Ukrainian official.