ABUJA, March 22 (Xinhua) -- At least four people were killed and 18 others injured when multiple suicide attacks hit a camp of internally displaced persons (IDP) in Nigeria's northern Borno State early Wednesday, a local welfare coordinator told Xinhua.

Borno State police chief Damian Chukwu said two blasts were heard at different locations of the IDP camp at 4:30 a.m. local time (0330 GMT) on Wednesday, and another one near a garage in Maiduguri, the state capital.

According to Chukwu, terror group Boko Haram, which has been blamed for more than 20,000 deaths and displacement of 2.3 million people in Nigeria since 2009, is suspected to be responsible for the attacks.

Coordinator of the IDP camp Tijani Lumani told Xinhua the explosions inside the camp triggered fire, burning down many tents.

There might be an increase of casualties as the rescue operation was still ongoing, he said. Security forces had cordoned off the area.

Last Saturday night, a suicide attack in the northeastern state of Borno had claimed four lives and injured eight local residents, police said.

The Nigerian government has made a considerable gain on the Boko Haram front, with its security forces operating in the restive region dislodging the fighters from the Sambisa Forest, the group's largest training camp in the country, last December.

Government forces are intensifying aerial and ground patrols in the country's northeast.