Thousands of police officers and soldiers have been deployed across the country following warnings that al-Qaeda-linked militants could be planning Christmas attacks.

A joint team comprising 2,552 personnel from the police, the Indonesian Military and local security guards have been deployed to ensure a safe Christmas and New Year's holiday in East Nusa Tenggara.

East Nusa Tenggara Police chief Sr. Comr. Robinson B. Sadarum said security would be beefed up at places of worship and public spots such as bus terminals, airports and shopping centers.

"Generally, security is under control but we are on alert to ensure safe Christmas and New Year's celebrations," he said.

Some 2,500 police officers, including snipers, are on alert in 21 regencies and cities in North Sumatra.

The chief of the North Sumatra Police, Brig. Gen. Bambang Hendarso, said snipers had been instructed to take "decisive" action against terrorists.

"Terrorist threats ahead of Christmas and the New Year should be taken seriously. We have deployed trained snipers in 21 regencies and cities considered at risk for attack," he said on Friday.

He said the officers would protect public places like shopping centers.

In Yogyakarta, roads leading to the city's 43 churches will be blocked off on Sunday morning, reopening after Christmas services are finished.

"Blocking off the roads is intended to ensure security for Christians who are celebrating Christmas," said Yogyakarta Police chief Sr. Comr. Condro Kirono.

He said that beginning Saturday, 1,600 police officers would guard the churches around the clock, adding that security would also be stepped up at mosques, shopping malls, hotels, traditional markets, train stations and offices.

The head of the Christmas celebration committee at Santo Antonius Kota Baru Church in Yogyakarta, ZP Heru Budianto, said his church would also involve local residents in protecting the church.

"We involve people from the village. Some 70 people will help guard the church," Heru said.

In Batam, Riau Islands province, police will be on guard at both churches and mosques.

The deputy chief of the Riau Islands Police, Sr. Comr. Sulistiyono, said on Friday the decision to increase security at mosques did not mean the police had information that specific Muslim groups were planning attacks, but was simply a precaution.

"Our decision to guard mosques is not intended to cast suspicion over certain Muslim groups, but is more of a precautionary measure," Sulistiyono said