HAIKOU - A tropical depression strengthened into tropical storm Mujigae early Friday morning and is still gathering power as it entered the eastern part of South China sea.

Weather services in south China's Hainan warned holiday tourists bathing in sunshine on the island's beaches that the storm threatens to bring strong gales and downpours from Sunday.

At 5 a.m., the storm was monitored at 15.9 degrees north latitude and 120.5 degrees east longitude, packing up strong winds with an instant speed of 64.8 kilometers per hour at its eye.

The southernmost island province is bracing for its golden travel week, as China's week-long National Day holiday started on Thursday. It host 2.18 million tourists during the holiday last week.