Complex sentence: On 27 June, the 2nd and 3rd Panzer Groups met near Minsk and captured the city the next day, completing the encirclement of almost all of the Western Front in two pockets: one around Białystok and another west of Minsk.
Split into simpler sentences: On 27 June, the 2nd and 3rd Panzer Groups met near Minsk and captured the city the next day. They encircled almost all of the Western Front in two pockets: one around Białystok and another west of Minsk.