The mayor of the South Korean capital Seoul has been found dead, hours after he was reported missing and police launched a massive operation to find him.

Park Won-soon was reported missing by his daughter on Thursday evening, according to a police official with knowledge of the case. Nearly 600 police officers and firefighters, along with three rescue dogs, were deployed to search for the mayor.

Park’s body was found in the city’s mountains seven hours into the operation, Seoul police confirmed in a text message early Friday to journalists.

Earlier search teams had scoured Waryong Park, where police he was recorded on CCTV footage at 10:53 a.m. on Thursday. His last cell phone signal was detected in the Seoul neighborhood of Seongbuk-gu, very close to his official residence in Jongno-gu, a police official with knowledge of the case said.

The 64-year-old longtime civic activist, who has been Seoul’s mayor since 2011, was seen as a likely hopeful for the liberals in the 2022 presidential elections.

When Park was elected in a landslide victory against the ruling party nearly a decade ago — with no political ties or experience — it sparked a public frenzy. His unexpected rise to the second most powerful position in the country was seen as a sign that South Koreans were tired of traditional politics.

The former human rights lawyer, who ran independently but forged an alliance with opposition parties, championed city welfare projects and became a symbol of reform.

He was reelected as mayor in 2014 and again in 2018.