Kabul ? Taliban militants are sowing fear along Afghanistan’s highways with stepped-up checkpoints, hijackings and bombs — including one Tuesday that killed at least 30 bus passengers in the south.

Afghan authorities say the attacks, often carried out by only a handful of militants, are part of a psychological campaign to convince civilians that Taliban control is spreading.

“It is quite possible for a group of three to five insurgents to come out on the highway and attack a convoy,” said the Interior Ministry spokesman, Zemarai Bashary. “Maybe thousands of people will travel that day and they are watching that convoy burning.”