Protests over unpaid salaries and reported retrenchment of more than 50,000 foreign workers at  leading construction group Saudi Binladin took an ugly turn on Saturday when the disgruntled workers burnt company buses in Makkah, said a report.

More than seven company buses were set on fire at Makkah in the latest protests, reported Arab News.

Major Nayef Al Sharif, the spokesman for the Civil Defence in Makkah, said late Saturday that firefighters put out the blaze without any injuries reported.

The Binladin Group has not issued any statements about the reported layoffs or the unrest.

For several weeks, thousands of the firm’s employees had been staging rare protests in Makkah and Jeddah, with some saying they have not been paid for six months, stated the report.

The attack comes a day after the company terminated employment for 50,000 foreign workers and issued them exit visas.

Among those laid off were engineers, foremen, steel fixers, carpenters and welders at the firm. Many of those workers are apparently refusing to leave without being paid their late wages, said the report.

Gulf-based construction firms have been among the hardest hit due to lower oil prices that have curbed and sometimes delayed government spending on major infrastructure projects, it added.