The death toll from a magnitude 6.8 earthquake that hit Luding county in Sichuan province on Monday has risen to 74, with damaged roads, aftershocks and rain hindering rescue work, which led to an upgrading of the emergency response to the second-highest level.

Forty people were killed in Luding in the Ganzi Tibetan autonomous prefecture, and the other 34 were in Shimian county of neighboring Ya'an city.

Fifteen people were missing and 253 were injured in Ganzi, including five in critical condition and 70 seriously injured, according to a news conference held by the information office of the Sichuan provincial government on Tuesday.

Houses and roads in Ganzi were severely damaged, power supplies to six townships were cut off, and one medium-sized and six small hydropower stations were severely damaged. More than 10 aftershocks have been recorded since the initial quake, according to the Ganzi prefectural government.

The Office of the State Council Earthquake Relief Headquarters and the Ministry of Emergency Management have upgraded the emergency response to the earthquake, which took place at 12:52 pm on Monday, to Level II, the second-highest level in the four-tier emergency response system.