MINGORA, Pakistan (Reuters) - Pakistani Taliban militants announced on Tuesday an indefinite ceasefire in the Swat valley in the northwest of the country, a day after the army said it was ceasing operations in the region.

In the neighboring Bajaur region on the Afghan border, the government announced a four-day ceasefire in response to a unilateral truce called by militants there on Monday.

The ceasefires are likely to compound concerns among Western countries which fear truces allow militants to create sanctuaries in Pakistan where they can regroup and intensify their insurgency against Western forces in neighbouring Afghanistan.

The indefinite ceasefire in Swat follows an agreement by authorities to enforce Islamic sharia law in the valley, which until 2007 was one of Pakistan's prime tourist destinations.

A 10-day truce announced in response to the agreement on sharia law had been made permanent, said a Taliban spokesman in the valley, 120 km (75 miles) northwest of Islamabad.

We have agreed on an indefinite ceasefire, said the spokesman, Muslim Khan.

Khan said the Taliban in the valley, led by militant cleric Fazlullah, also decided to release three people, including two politicians, as a goodwill gesture.

The militants had virtually taken over control of the valley in recent months, residents said, killing enemies and blowing up schools which they said the security forces were using as posts.

The army said on Monday it had ceased operations against militants in Swat and said there would be no sanctuary for militants there if the writ of the state was re-established.

While militants negotiated from a position of strength in Swat, in the Bajaur region they had been hard pressed by security forces in recent months and declared their ceasefire after they appeared to have been cornered.

FOUR DAYS

Bajaur has long been a major infiltration route for militants into eastern Afghanistan. Major-General Tariq Khan, the head of the paramilitary Frontier Corps, told Reuters on Monday his forces were expected to clear the region by March.

The military has said more than 1,500 militants and nearly 90 soldiers have been killed in Bajaur since last August. There was no independent verification of the militant casualty estimate.

Responding to the militants' ceasefire declaration, civilian and military officials said security forces would hold their fire for four days to allow Pashtun tribal elders to persuade the militants to lay down their arms.

A security analyst said the forces had to be vigilant because militants from Swat could slip over mountains into Bajaur to help their comrades.

They have to watch Bajaur very critically and their normal operations should continue, said Mahmood Shah, a former security chief in the Pashtun tribal areas.

They shouldn't have even given them four days and should have asked them straight away to lay down arms.

Authorities have struck peace deals with militants in several parts of the northwest over recent years, including one in Swat last May, but none has succeeded in eliminating militant sanctuaries.

Fighting flared in Swat, which is not on the Afghan border, in 2007 after hundreds of militants turned up from border enclaves to support Fazlullah and his drive to introduce hardline Islamist rule.

The government said this month 1,200 civilians and 180 members of the security forces had been killed in the valley since 2007.

The human rights group Amnesty International said between 200,000 and 500,000 people had been displaced from their homes in Swat by the violence.

(Writing by Zeeshan Haider; Editing by Robert Birsel and Paul Tait)

Pakistan Afghanistan