COLOMBO, Sri Lanka (CNN) -- Tamil Tiger rebels launched a deadly land and air attack on a Sri Lankan air base early Monday in the northern part of the country, triggering explosions and damaging aircraft, military sources said.
The attack at the air base at Anuradhapura began at 3:10 a.m. with rebels infiltrating the base in the country's north central province.
Residents in the area, who spoke by telephone, said they heard loud explosions and heavy gunfire. Shortly after the ground attack began, a rebel aircraft bombed the base, the sources added.
Police enforced an unofficial curfew for the area which has been sealed off as fighting continues.
Seven Sri Lankan Air Force personnel have been killed, including an officer and two airmen on the base, a military source said.
Four crew members on a Sri Lanka Air Force Bell helicopter were killed when their aircraft crash landed in Mihintale, near Anuradhapura. The immediate cause of the crash was not known.
There has been no official response to the incident so far except an admission by Defence Ministry sources that an attack had taken place. Officials downplayed the incident saying a small group had staged an attack.
Military sources said two Mi-24 helicopter gunships, a U.S. built Beechcraft reconnaissance plane and a Chinese built K-8 fighter jet, were damaged. However, air force officials declined comment.
Monday's strike was the first major attack on an air force base since the rebels demonstrated their air strike capability in March this year. The move, analysts say, is a direct retaliation for the month long raids on rebel positions by air force bombers.
It was only a week ago the rebels attacked an army detachment in southern Sri Lanka killing six soldiers.
Since 1983, the Tiger rebels have tried to create an independent state for the country's ethnic Tamil minority, who have faced discrimination by successive majority Sinhalese-controlled governments. The Associated Press reports more than 70,000 people have been killed during the conflict. E-mail to a friend
Journalist Iqbal Athas contributed to this report.
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