Apple has asked a court to ban eight Samsung mobile phones in the US.
The phones include the Galaxy S 4G, Galaxy S2 AT&T model, Galaxy S2 Skyrocket, Galaxy S2 T-Mobile model, Galaxy S2 Epic 4G, Galaxy S Showcase, Droid Charge and Galaxy Prevail.
It comes in the wake of Apple's US court victory over its rival, which saw the South Korean company ordered to pay $1.05bn (£655m) for copying patents.
Apple shares rose 1.88% to $675.68 in Monday trading on Wall Street.
The company has asked the US District Court in San Jose, California, for a preliminary injunction on the Samsung products, while a permanent injunction is sought.
At the same time, Samsung has also asked the court to delete an injunction on its Galaxy Tab 10.1, after the jury in the recent court case found it did not infringe Apple's design patent for the iPad tablet.
Judge Lucy Koh had issued an injunction on the tablet on 26 June.
Earlier on Monday, Samsung sent a memo to staff hitting out at what it called the "abuse of patent law".
Shares in Samsung fell 7% in Seoul trading, their biggest one-day fall in almost four years.
On 24 August, a US court ruled that Samsung had infringed Apple patents for mobile devices in one of the most significant rulings in a global intellectual property battle.
Samsung said it would be appealing against the verdict.
"We initially proposed to negotiate with Apple instead of going to court, as they had been one of our most important customers," the company said its memo to staff.
"However, Apple pressed on with a lawsuit, and we have had little choice but to counter sue, so that we can protect our company."
It said that the US court's verdict contrasted "starkly" with decisions made in other countries, including the UK, the Netherlands and Germany.
"History has shown there has yet to be a company that has won the hearts and minds of consumers and achieved continuous growth, when its primary means to competition has been the outright abuse of patent law, not the pursuit of innovation," the memo said.
"We trust that the consumers and the market will side with those who prioritise innovation over litigation, and we will prove this beyond doubt."
Analysts said investors were worried that the ruling could see certain products taken off the market.
"An adjustment in the next few days is unavoidable as the damage amount was much bigger than market expectations, and there are further uncertainties, such as the possibility of a sales ban," said John Park, from Daishin Securities.
In a separate move, the giant chipmaker ASML said Samsung would be investing $975m in its research programme into next-generation chipmaking technology and in buying a 3% share in the company.
Intel Corp and TSMC have both recently signed similar investment deals into the co-investment programme, whose aim is to tie in ASML's customers and develop new technology designed to lead to cheaper products.
A nine-member jury in San Jose, California ruled on 24 August that Samsung had infringed Apple patents for mobile devices.
It was the the most closely-watched of many similar patent disputes being contested in courts around the world between electronics manufacturers.
In recent weeks, a court in South Korea ruled that both Apple and Samsung had copied each other, while a British court dismissed claims by the American company that Samsung had infringed its copyrights.