LISBON, Portugal (AP) -- Portuguese tanker truck drivers have announced a new walkout, just days after returning to work and resuming talks with employers in a pay dispute.

The Hazardous Materials Drivers Union said Wednesday its about 750 members -- from a total of some 900 in Portugal -- will refuse to work overtime and on weekends and public holidays Sept. 7-22.

The union says truckers work many overtime hours to keep the country's 3,000 gas stations stocked.

Truckers ended a seven-day walkout on Sunday, after government emergency measures prevented gas pumps from running dry. Talks with employers broke down late Tuesday.

A spate of strikes has tested the Socialist government, traditionally sympathetic to trade unions. But with a general election less than two months away, the center-left government is wary of taking sides.