Egyptian security forces killed 40 militants in two operations after four people died in a roadside bomb that struck a tour bus in Greater Cairo.

The militants were planning attacks against churches, state institutions, economic interests, the armed forces and tourist sites, the Ministry of Interior said in a statement on Saturday. The operations took place in northern Sinai and Giza.

Three Vietnamese nationals and an Egyptian tour guide were killed in the bombing attack on Friday, the state-run Ahram Gate reported, citing a statement from the country’s Public Prosecutor Nabil Sadeq.