RIO DE JANEIRO, Sept. 10 (Xinhua) -- At least 105 inmates escaped from a maximum-security prison in northeast Brazil on Monday after assailants blasted their way through the front gates, officials reported.

According to the regional Secretary of Social Defense (SEDS), some 20 armed assailants arrived at the Romeu Goncalves Abrantes Prison in Joao Pessoa, capital of Paraiba state, aboard four vehicles, and began shooting at the guard towers.

While breaking down the five-meter-high gates with explosives, another contingent blocked the access road to the prison, the SEDS said.

Police suspect the operation aimed to rescue four inmates who were arrested last month, and who specialize in assaults against vehicles, safes and ATMs.

One police officer was shot in the head, sustaining serious injury, the SEDS said.

At least 33 of the escapees were later captured, but the rest remain at large, prompting local authorities to cancel classes at nearby schools and universities, as well as health clinics "to guarantee the security of the healthworkers and patients."

The 660-capacity prison currently houses 680 inmates.