The state government on Saturday banned all inter-state bus operations with neighbouring states from midnight till March 31.

All inter-state bus operations “originating from the state” would remain suspended till the end of March, an order issued by the transport department said.

The order, issued by the transport secretary, also said that inter-state buses originating “in the neighbouring states” shall not be allowed to enter Bengal till March 31.

While some senior officials in the department said “neighbouring” meant those states with which the Bengal government has a reciprocal arrangement for running buses, no one was clear about which states were to be considered as “neighbouring”.

“We have reciprocal arrangements with Odisha, Jharkhand, Bihar along with Assam and Sikkim,” said a senior official of the department. “The order assumes these as neighbouring states.”

Inter-state buses, including those for destinations in Odisha, Jharkhand and Bihar, leave from terminuses at Esplanade, Babughat and Karunamoyee. Similar terminuses are also located in Siliguri and Malda.

While most of these buses are run by private operators, the North Bengal State Transport Corporation and its counterpart in south Bengal, too, operates a few buses.

Late on Saturday, a copy of the order issued in the evening was sent to the director general of police along with district magistrates, police commissioners and regional transport officers.