Police motor-cycles stand idle outside a Bangkok police station yesterday. The rising cost of fuel may see them remaining unused for some time as police officers turn to patrolling on foot and on bicycle to keep costs down.

Wiroj said the city's police would continue to protect people's lives and property in Bangkok but, facing oil price hikes, would have to adjust and be more energy efficient.

A bigger fuel budget will be requested from the government, and in the meantime officers will make as many patrols as they can on foot, or on bikes, he said.

Wiroj dismissed allegations police used fuel paid for by the government when they were off-duty.

Royal Thai Police spokesman Ajirawid Subarnbhesaj said the police would adjust their work system to take into account higher fuel prices.

He said email warrants would be issued in emergency cases, because in some areas courthouses, where warrants are issued, are up to 100km away from the stations where the investigating officers are based.

Civilian volunteers would also be used more often, said Ajirawid.

"We used to be able to buy 600 litres [of fuel] a month, but now we only get 300 litres per month ... We'll try to adjust our operations and encourage more people participation," he said.

In Khon Kaen, traffic police have launched the "officers patrolling on bicycles" project, using 37 bicycles provided by the provincial administration.

There have been "satisfactory" results so far, said Muang Khon Kaen deputy superintendent Lt-Colonel Khanit Duanghassadee.