(2nd UPDATE) President Rodrigo Duterte poked fun at former president and Manila Mayor Joseph Estrada, "threatening" to have him detained again.

"Si Erap, naghihintay na 'yung buang. Birthday niya ngayon eh. Sabi niya, punta ka talaga ha," Duterte joked during an event in Pasay City on Wednesday.

He then recalled what Estrada allegedly said when he was still a presidential candidate.

"Tapos noon sabi niya, 'o wala 'yang si Duterte. Ano 'yan, low-class lang 'yan. Ano 'yang style niyan,'" Duterte said.

"Ngayon...ibalik kita sa kulungan," he joked.

Duterte later attended Estrada's 80th birthday celebration Wednesday night.

Photos from Duterte's top aide, Christopher "Bong" Go, showed the President with other VIPs during Estrada's birthday party.

Present during the Manila mayor's birthday celebration were former president Gloria Macapagal Arroyo and her husband Mike Arroyo, former first lady Imelda Marcos, former vice-president Jejomar Binay, and former senator Bongbong Marcos.

Estrada was detained after he was impeached in 2001. He was given an unconditional pardon in 2007 by then president Gloria Macapagal-Arroyo.

Pres Duterte celebrates 80th bday of Manila mayor Joseph estrada at Manila hotel @abscbnnews pic.twitter.com/6u6QXgB5UD

— Mario Dumaual (@mariovdumaual) April 19, 2017