Manila, Dec 11 (IANS): Philippine President Rodrigo Duterte on Monday asked Congress for a one-year extension of the martial law imposed in the southern region of Mindanao, where Islamic State (IS) militants laid partial siege to a city for five months.

Duterte's proposal comes 20 days ahead of the end of the current period of martial law, and he has asked for its extension until December 31, 2018, with the aim of containing rebels linked to the IS and the growing threat of communist insurgency, reports Efe news.

"Public safety indubitably required such further extension, not only for the sake of security and public order, but more importantly to enable the government and the people of Mindanao to pursue the bigger task of rehabilitation and the promotion of a stable socio-economic growth and development," he said.

Filipino lawmakers are scheduled to meet before the end of the year to vote on the President's proposal.

Duterte had declared martial law on May 23, the day the Maute group took up arms and laid siege to Marawi, Mindanao.

The initial period, limited to 60 days as required by the country's Constitution, was extended until the end of the current year by lawmakers in July.

The Philippine Armed Forces liberated the city after five months of clashes that left more than 1,100 dead and caused widespread destruction in the city that had a population of around 200,000 before the conflict.