FAA staffing shortages and runway construction caused hundreds of flight cancellations and delays at Newark Liberty International Airport in New Jersey on Thursday.

The FAA said the issue was first prompted by telecommunications and radar equipment issues at Philadelphia Terminal Radar Approach Control, which guides aircraft in and out of Newark. Both have been resolved but now there are staffing issues at Philadelphia impacting flights, the FAA said.

Newark Liberty International Airport reported another brutal afternoon of flight delays. Thursday’s troubles follow a similar Monday headache.