By Susannah Price
BBC News, United Nations
The UN Security Council has voted unanimously for UN peacekeepers in Liberia to detain ex-President Charles Taylor if he returns to the country.
Taylor still retains popularity in his home country
Mr Taylor, currently in exile in Nigeria, was indicted by a UN-backed court in neighbouring Sierra Leone for crimes against humanity there.
US-based group Human Rights Watch says the resolution is a big step forward.
Charles Taylor has scarcely figured in the recent elections but his future remains a highly contentious issue.
The resolution stresses the fact Mr Taylor remains indicted on 17 counts of war crimes and crimes against humanity by the UN-backed court in Sierra Leone.
Nigeria has refused to hand him to the court, saying it would contravene the terms of the deal under which Mr Taylor agreed to step down.
Under the resolution, UN peacekeepers in Liberia are mandated to detain Mr Taylor if he returns to Liberia and to transfer him to Sierra Leone for prosecution.
Russia's ambassador to the UN, Andrei Denisov, said council diplomats stressed the need to reverse the culture of impunity.
Analysts say it is hoped the resolution would deter Mr Taylor from returning to Liberia, which could be very destabilising.
Elise Keppler of Human Rights Watch said the resolution sent a strong signal to Nigeria's President, Olusegun Obasanjo, that he should surrender Mr Taylor to the court.
However, as the court is facing funding problems, she warned that time was of the essence.