Pakistani troops and rescue workers continued their struggle on Sunday to help more than one million victims of monsoon-triggered floods in the country's southwest.

At least 50 people were feared dead in the latest flooding in Baluchistan province, the BBC reported.

A Pakistani navy ship rescued 265 people from Ormara and other coastal areas of Baluchistan, a navy official said.

Zulfiqar Ali, a flood survivor, said he and others were trapped on the Angora bridge.

"We were stranded there for two days. Then the navy was informed, which brought us to Ormara. They really helped us," Ali said.

Earlier, 122 people including women, children and elders, were rescued and brought to Karachi.

In total the floods have left as many as 100 people dead in southwestern Pakistan, a senior relief official said on Sunday, as the government appealed for donations of tents to shelter about 1.3 million people left homeless by the flooding.

The deaths have occurred in the southwestern province of Baluchistan since Tuesday, when Cyclone Yemyin and rains triggered floods across a vast area, said Tariq Ayub, Baluchistan's home secretary, who is overseeing the flood relief operation.

Authorities said many of the casualties occurred due to drowning and people getting trapped under the debris of their collapsing homes.

With roads washed away by the flood waters, leaving hundreds of villages cut off by swollen rivers, army helicopters have been flying over the affected areas and dropping tents, food and clean water to stranded villagers.

But more heavy rains are expected in the normally arid areas around the coastal town of Turbat, about 650 kilometres southeast of Quetta, leaving rescue workers in a race against time to get as much aid to victims as possible before they are cut off by floods once again.

Workers from a local welfare group, the Edhi Foundation, have formed mobile kitchens and are touring villages, supplying the hot meals and clean water.

Villagers elsewhere said they were still waiting for aid to arrive.

Water unsafe to drink

Officials have said a large number of people in Baluchistan's flood-hit area had no access to safe drinking water, raising the possibility of waterborne diseases.

A Pakistani navy spokesperson told reporters that rescue and relief operations were underway along the coastal belts of the Baluchistan.

He said the PNS Kalimaat, carrying food aid, had reached Ormara, and two medical camps were being set up in Gawadar and Pasni.

According to Pakistan's Meteorological Department, a fresh spell of rain which began in the flood-affected areas is expected to continue for two or three days.

Floods last week also killed more than two dozen people in Pakistan's northwestern tribal region.

On June 23, storms left 228 people dead in Karachi, the capital of neighbouring Sindh province.