KATHMANDU: Police on Monday seized as many as 12,000 units of illegal firecrackers from Naagdhunga check point on the western outskirts of Kathmandu. While Nepalis are celebrating the Dipawali to mark the annual Tihar festival, police have intensified a crackdown on illegal trade of firecrackers in Kathmandu Valley of late. The illegal firecrackers were hidden in a carton inside a sack on the passenger bus (Na 6 Kha 9009) which had left Dharan of Sunsari for the Capital, police said. The contraband was seized during a routine security check. Police said further investigation is underway.