<p>MIAMI — Dozens of heavily armed police officers surrounded a hijacked mail truck after a 90-minute slow-speed chase through the city's streets Friday.</p>
<p>The chase began after witnesses reported seeing an armed man jump into the truck, police said. Television station WFOR-TV reported that a female mail carrier was being held at gunpoint, and a television helicopter shot showed two guns in a mail bin on the passenger's seat.</p>