Yemen’s internationally recognised government has announced the start of a major military offensive against the Houthi movement. The aim is to reclaim territory held by the Iran-backed group and restore state authority.

President Rashad al-Alimi made the announcement in a televised address on Sunday. He said forces would fight until the country is freed from the group’s grip. A military spokesman called it a battle for liberation.

The Saudi-led coalition has pledged full support to the offensive. Reuters reported that government forces have seized parts of Dhubab district, which overlooks the Bab el-Mandeb strait, with heavy Saudi air support.

The Houthis have held the capital Sanaa and much of the northwest since 2014. Last month they captured a key Red Sea port, raising fears over shipping safety. The group has claimed missile and drone strikes on Saudi Aramco sites, which Riyadh has not confirmed.

The renewed fighting has forced tens of thousands from their homes. The World Food Program says three of every four families in parts of Yemen are going hungry because of the surge in fighting.