The South Korean government on Thursday expressed concerns over escalating violence and civilian deaths amid military conflict between Israel and the Palestinians.

"We express grave concern over massive civilian casualties, including children, caused by indiscriminate rocket attacks in the Gaza Strip and counterattacks against them," the foreign ministry said in a statement.

"We call on the both sides to refrain from raising tensions and stop using armed forces, as violence cannot be justified under any circumstances," it added.

Days of tense clashes that have spiraled into aerial conflict between Israel and Palestinian militants have killed more than 50 people and injured nearly 500. Many of the victims are civilians, including children.

The ministry said no Korean casualties have been reported.

"Korean nationals residing in Israel and Palestine are under safe conditions so far," a ministry official said.

Currently, there are a combined 470 South Koreans in Israel and in the State of Palestine, according to the ministry. (Yonhap)