Police Headquarters has issued a nationwide alert warning of possible attacks on police vehicles by members of extremist groups or other miscreants and instructed all police units to strengthen security measures.

The directive was issued in an urgent message from the Operations Control Room of Police Headquarters on Saturday.

According to the message, intelligence indicated that police vehicles, including jeeps, pickup trucks and buses, could be targeted.

To prevent such incidents, Police Headquarters instructed that any police vehicle temporarily halted during duty must, as far as possible, be parked in a secure location and kept under police surveillance. It also directed that vehicles must not be left unattended.

The directive further asked all police units to enhance security for vehicles parked inside police stations, office compounds and police lines after duty hours.

Describing the matter as "highly important", Police Headquarters asked all concerned to implement the instructions with utmost priority.

When contacted, Additional IGP (crime and operations) Khondker Rafiqul Islam told The Daily Star the directive was issued as a precautionary measure.

“There may be programmes by banned organisations centring on the month of August. That is why this precautionary instruction has been issued," he said.