Image copyright AP Image caption The inmates escaped from the North Cotabato District Jail in Kidapawan city

More than 150 inmates have escaped from a south Philippines prison after gunmen launched an attack.

The authorities suspect the gunmen are linked to Islamist separatist groups.

Around 100 armed men stormed the jail and engaged in a shoot-out with guards, as prisoners fled in the chaos. A guard and six escapees were killed.

The Philippines, which is predominantly Catholic, has battled separatists in the south for decades, amid kidnappings, violence and jailbreaks.

The latest prison break took place at the North Cotabato District Jail near Kidapawan city, on the island of Mindanao.

Image copyright Reuters Image caption One guard died during the jailbreak, and six escapees were also killed

Prison authorities said the gunmen showed up around 01:00 local time (17:00 GMT Tuesday), opening fire on the facility, which held more than 1,500 men.

The shoot-out lasted for about two hours, and in the confusion some prisoners fled to the back of the prison and climbed over the walls by stacking their beds, reported GMA News.

Jail warden Peter Bonggat told AFP: "The [inmates] took chances because of the volume of fire. They used their bedding, piled them on top of each other to escape."

He added that he believed the attack was to free a number of Islamist rebels who were in the jail.

Philippine military and police have launched a hunt for the escaped inmates. At least six have been recaptured.

History of jailbreaks

It was the third and biggest prison escape in the past decade at North Cotabato District Jail, according to the Philippine Star newspaper.

More than 40 inmates fled in 2007 when three bomb-makers were rescued by guerrillas, and four years later another group of bomb-makers also escaped.

The south of Philippines has a history of violent jailbreaks in general.

In August last year Muslim extremists supporting the Islamic State militant group freed eight detainees and 15 other inmates at a jail in Marawi, a city on Mindanao.

Islamist groups like the Moro Islamic Liberation Front (MILF) and Abu Sayyaf have conducted terror attacks as well as kidnapping tourists for ransom in southern Philippines for decades.

The MILF is in the midst of a long-running peace process with the Philippine government, but it has been hampered by the fact that the group has splintered into several factions and offshoot groups, some of which have refused to surrender.