At least one policeman was killed and four others were wounded Wednesday in a series of explosions in the northeastern state of Assam, officials here said.

A police spokesman said there were eight blasts in different parts of the state. Three of the explosions took place in Assam's main city of Guwahati. 

Militants triggered three blasts in the heart of Guwahati between 7 p.m. and 8 p.m. - one outside a local police station, another near a hospital, and the third outside the Gopinath Bordoloi International Airport.

"Fortunately the explosions missed the targets as there were no people at that time," a senior police official told IANS.

"The blast at the airport damaged a portion of the wall in the parking lot. There were no casualties as the airport was closed by then."

Police blamed all the blasts on the outlawed United Liberation Front of Asom (ULFA), which is fighting for an independent homeland in Assam since 1979. 

"We have intelligence reports that the ULFA was planning an attack ahead of their 'military raising day' on March 16," the official said. 

In Assam's western district of Bongaigaon, a policeman was killed and four more were wounded. 

"There was a bomb planted in a market and when the police team was about to defuse the device, it went off killing one and injuring four," a police official said.

There were also three explosions in eastern Assam's Sibasagar district.

"Three bombs planted beneath a transmission tower went off damaging the power installation," said Sibasagar district police chief Debojit Hazarika. 

Another blast in eastern Assam's Nagaon district damaged a telephone exchange.