Two Palestinian teens were arrested Saturday night at a West Bank checkpoint after police found they were hiding pipe bombs, a gun and ammunition, authorities said.

The Palestinians, both 17 and residents of the Balata refugee camp in Nablus, were acting suspiciously as they approached the Tapuach Junction on Saturday evening. When asked to stop for a routine inspection they attempted to run away, but were caught by Border Guards and police officers, according to reports.

They were discovered to be carrying five pipe bombs, a gun and ammunition. One of the teens was also carrying a knife.

It is believed that they were planning a large scale attack. Jewish buses traveling in the area on Saturday night are often full and there is a busy hitchhiking post near the checkpoint.