MANILA (UPDATE) - Manila Mayor Isko Moreno Domagoso on Thursday postponed his planned oath-taking with Aksyon Demokratiko to address "chaos" at a vaccination site in Manila.

"Mayor Isko Moreno Domagoso decided to put off the Aksyon oath-taking which was scheduled this afternoon," Domagoso's chief of staff Cesar Chavez told ABS-CBN News.

"The chaos in some NCR vaccine centers, especially in Manila this morning, requires utmost collective attention," he said.

The leadership of Aksyon Demokratiko has been notified about the postponement of the event, he said.

The Manila Mayor's oath-taking "will be rescheduled soon, most likely after the Enhanced Community Quarantine," Aksyon Demokratiko Secretary General Ernest Ramel Jr. said.

"The oath-taking is just ceremonial. The National Executive Board will convene prior to the 15th to elect its new set of officers," he told ABS-CBN News in a text message.

The election will "most likely" be held online "because of the bubble and travel restrictions," he said.

• Isko Moreno to join Aksyon Demokratiko ahead of 2022 elections

Domagoso was supposed to formally join Aksyon Demokratiko on the 16th death anniversary of party founder and late senator Raul Roco, but had to "call off" the event before noon after thousands trooped to vaccination sites in Manila a day before the capital region was placed under the strictest lockdown classification.

Chaos reportedly ensued in the capital city after police announced the decision of the local government to cancel Thursday’s vaccination at the SM Manila, SM San Lazaro, Lucky Chinatown Mall and Robinsons Place Manila, angering thousands who have been in line before dawn.

• Manila LGU cancels SM San Lazaro vaccination, won't accept walk-ins in 3 other malls

Askyon Demokratiko and other political parties must finalize their list of officers and members before the Commission on Elections' (Comelec) August 15 deadline for the submission of the Sworn Information Update Statement (SIUS).

The SIUS - a document stating the party's office details, list of officers, list of elected members, and other details— is meant "to ensure that those in the registry are still in existence and continue to comply with the requirements of the Constitution," the Comelec said in an earlier circular.