MBTA officials who initially said delays on the Red Line would continue "at least through Labor Day" are now targeting sometime in October for restoration of full service.

Some progress has been made to repair signal infrastructure damaged by a June 11 derailment, and the Red Line is now running as many rush hour trains as it normally does, albeit at slower speeds. However, MBTA General Manager Steve Poftak said Monday he expects it will take about another two months to return the entire system to fully automated electronic signals.

"We are currently running a full schedule of trains during rush hour, 28 trains," Poftak told reporters at a South Station event, according to audio provided by the MBTA. "However, because they are still manually signaled through several major portions of the route, it's obviously slower than we'd like. We are still working really hard to get everything back. We expect everything to be back at some point in October."

Poftak said that several "incremental repairs" between now and the fall should help reduce delays, which were initially forecast at 10 to 20 minutes in the wake of the derailment when fewer trains were running.

Signals between JFK/UMass, where the derailment occurred, and Broadway were restored recently, a project that MBTA officials said should trim five minutes off most trip times.

A T spokesman said Monday that there is no updated estimate of delays because workers first need to analyze trip time data now that a full 28-train rush hour fleet is running.

"We have a number of incremental repairs that we hope will improve trip times," Poftak said. "Right now, we've got the capacity up to where it was before, but the trains just aren't running as quickly as they can when we are automatic."

Officials still have not announced the cause of the derailment, which saw a train with 60 passengers on board damagetwo signal bungalows and destroy a third. Investigators ruled out foul play, operator error and a problem with the track infrastructure, and are now examining whether the 50-year-old car or its wheel truck were responsible.

A metallurgic analysis has been underway for weeks to help determine which components broke down as a result of the derailment and which might have caused it. The derailment was the fifth this calendar year on an MBTA passenger train and the 24th since 2015.

The ongoing delays have created significant frustrations for riders who already contend with semi-regular disruptions. Boston Mayor Marty Walsh urged the MBTA to make a roughly $9 million investment in running more frequent trains to offset disruptions, calling the system "not currently a functional service" in a letter to Poftak last month. But after meeting with the GM, it is not clear if his request will be fulfilled.

T officials rejected calls for a pause on fare hikes that took effect July 1 or some other financial relief to Red Line commuters, describing the additional $30 million from higher fares as important to the agency's finances. The MBTA learned late last month that it stands to gain about $23 million more this fiscal year than state budgeters previously thought.

Asked if the T would consider any commuter relief options with signal work continuing into October, spokesman Joe Pesaturo said the agency's focus was on repair work.

"The MBTA understands the frustrations customers have experienced, and that's why the T's entire focus is on continuing to make incremental service improvements between now and the full restoration of automated signaling," Pesaturo wrote in an email.

Referring to riders, Poftak said Monday that he "really appreciate(s) their patience."

"We know how frustrating this has been," he said. "It's been frustrating for us, and having ridden the Red Line a bunch of times, I understand how frustrating it is for commuters."

The extended delays on the Red Line may continue long enough to overlap with debate at the State House on new ways to generate revenue for transportation needs, something House Speaker Robert DeLeo promised to take up in the fall.

Lawmakers have yet to act on a bill (H 3934) Gov. Charlie Baker filed in June seeking $50 million for short-term, accelerated improvements to the T.

Both branches embarked on a recess last week, and legislative leaders have not signaled when they plan to resume formal sessions.