Note que "pedimos" pode ser "presente do indicativo" (ask) ou "pretérito perfeito" (asked).
I translated as close surveillance but it insisted on tight. Am I missing something ?
I'm not sure they are synonyms. Are they?
For "close" I'd use "nós pedimos que vigiassem de perto"
Apertada is not quite the word here, it would be better to use "acirrada".