Qantas on Thursday said 8,500 passengers would be hit by renewed ground staff and engineer strikes which have forced two flights to be axed and 39 others delayed on one of the year's busiest weekends. Some 4,000 Transport Workers Union (TWU) members were to walk off the job for an hour from 8am Friday (2200 GMT Thursday) -- the morning peak -- with engineers in Melbourne to strike from 6-7pm over stalled contract talks. It is the second major strike to hit the embattled airline in as many weeks, and follows separate stop work action by government-employed border security staff across Australia on Tuesday, delaying international travellers. Qantas media chief Olivia Wirth said the strike would again hit international passengers, condemning the TWU for walking out on one of the year's busiest days for air travel. It is school holidays and a three-day weekend in Australia, and the popular Aussie Rules and National Rugby League football codes are holding their grand finals, the latter involving the New Zealand Warriors team. "This really couldn’t have come at a worse time with passengers trying to get to the AFL and NRL Grand Finals and many families heading away for the school holidays," Wirth said. "We’re sorry that the TWU is taking their grievances out on our passengers over a pay dispute. We are doing everything we can to minimise the disruptions." Managers would again be dispatched to catering and baggage handling roles, Wirth added. Rolling stoppages by border security and quarantine staff which saw thousands of employees walk off the job earlier this week continued Thursday at Sydney International Airport as talks over pay failed to progress. Hundreds of Community and Public Sector Union members stopped work in the morning and planned to do so again for an hour in the evening in Sydney, with threats to repeat the same strike schedule on Saturday. Qantas is facing industrial revolt from all three of its staff unions -- the TWU and those representing pilots and engineers -- following the announcement of an Asia-focussed restructure that will see 1,000 jobs axed. Only pilots are yet to escalate their dispute over future pay and conditions to full-blown strikes.