Seoul, South Korea (CNN) -- North Korea launched two short-range rockets off the east coast of the Korean peninsula on Wednesday, according to the South Korean Defense Ministry.
The projectiles flew for about 180 kilometers (110 miles) before falling into the sea, officials said.
North Korea has carried out a series of missile and rocket launches into the sea in recent months, drawing criticism from South Korea, the United States and the United Nations.
The latest launch comes the day after South Korea dismissed a North Korean "special proposal" to improve ties and reduce military tensions. Seoul said the North's request was based on irrelevant and inaccurate claims.
The proposal asked South Korea to halt intrusions at sea and firing drills near islands close to the two countries' disputed maritime border.
North Korea also wanted South Korea to stop "attracting" U.S. military hardware, including strategic bombers and a nuclear-powered aircraft carrier, into the region. It asked that South Korea cancel its planned joint military drills with the United States in August.
"Our people and the international community clearly know that the fundamental threats to the peace in the Korean peninsula and the future of our people are North Korea's nuclear and missile development," the South Korean Unification Ministry said.
"If North Korea truly wishes for peace in the Korean peninsula, not only should it stop its slander and threats of provocation, it should also show its sincerity in resolving nuclear issue," the ministry said.
Tensions over drills
Park Soo-geun, a former South Korean military official, said Pyongyang might have fired the rockets Wednesday because of Seoul's refusal to accept the proposal.
"North Korea has been continuously been pressuring the South to halt its joint military drills with the U.S.," he said.
Seoul and Washington have rejected previous demands from North Korea for joint U.S.-South Korean drills to be called off.
Tensions have flared periodically between the two Koreas in recent months, notably along their maritime boundary, known as the Northern Limit Line.
In late March, the two sides both fired hundreds of shells across their western sea border.
Last month, the South Korean Navy fired warning shots after three North Korean patrol boats crossed the line. And a few days later, North Korea fired at least two shells near a South Korean patrol boat in the Yellow Sea.
North and South Korea remain technically at war since the Korean War ended in a cease-fire, not a peace treaty, in 1953.
CNN's K.J. Kwon reported from Seoul, and Jethro Mullen wrote from Hong Kong. CNN's Susanna Capelouto contributed to this report.