Fear!

"Master, there are bandits before us, 30 of them!" One of the servants shouted as the remaining four grabbed their weapons and shields, intending to protect the horses first. As long as they retained their mobility, they wouldn't be surrounded and be placed in a dangerous situation.

The bandits hadn't arrived at their front alone. But, they were also on their back, preventing them from escaping. And, they had timely arrived at a far-off place, revealing their location first.

This was in an effort to scare the passengers by making them feel their front and back were blocked. Typically, the passengers might try to run off into the forest. And, this was exactly what they preferred. After all, they knew the forests quite well and would track the people, capturing them once they had tired themselves by running through the forest terrain.