(CNN) -- The number of people killed when a bus carrying Czech vacationers crashed in Croatia has climbed to eight, a Czech foreign ministry spokesman said Saturday.
More than 40 people were injured, said Karel Srol, deputy spokesman for the Czech Republic's foreign ministry.
The bus was chartered by Atlas Adria travel agency, he told CNN.
The 51 passengers were on their way from the Czech Republic to a summer holiday in Croatia when the crash happened Saturday morning, he said.
"Our embassy in Croatia is closely monitoring the situation. Diplomats and consular staff are en route to the scene of the incident and are visiting some of the injured in hospitals," Srol said.
The cause of the accident is not yet known.
CNN's Elizabeth Joseph contributed to this report.